Ophthalmic brachytherapy systems and devices for application of beta radiation

ABSTRACT

Systems and devices for applying radiation to a target area, for example for maintaining functioning drainage blebs or functioning drainage holes in the eye, e.g., to reduce intraocular pressure (IOP) of an eye being treated for glaucoma. The systems and devices of the present invention provide for the application of beta radiation to the target area, wherein the beta radiation can function to inhibit or reduce the inflammation and/or fibrogenesis that may occur after insertion of an implant into the eye or introduction of a hole for the purpose of draining aqueous humor to maintain a healthy intraocular pressure. By reducing inflammation and/or fibrogenesis, the implant, the hole, the blebs, or other related structures or tissues can remain functioning appropriately.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a non-provisional, and claims benefit of U.S. PatentApplication No. 62/772,741 filed Nov. 29, 2018, the specification(s) ofwhich is/are incorporated herein in their entirety by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to systems and devices for applyingradiation to a treatment area, e.g., for applying beta radiation to helpmaintain functioning blebs and/or drainage holes arising from glaucomadrainage procedures or surgeries, to help avoid scar formation or woundreversion, to inhibit or reduce fibrogenesis and/or inflammation in theblebs or surrounding areas, etc.

Background Art Glaucoma

Glaucoma is the leading cause of irreversible blindness and represents afamily of diseases with a characteristic optic neuropathy. Therapy forthis group of diseases is principally focused at reducing theintraocular pressure (IOP) of the fluid inside the eye (aqueous humor),thus averting ongoing damage to the optic nerve.

Glaucoma is managed by attempting to lower the intraocular pressure(IOP). In the USA, Europe, and some other industrialized countries, thefirst line therapy is typically medication delivered by eye drops. Suchmedications include beta-blockers, prostaglandins, alpha-adrenergicagonists, and carbonic anhydrase inhibitors. For patients who failmedication and in other parts of the world where there are economic anddistribution barriers to the practicality of daily medication andfrequent follow up, the treatment regime is primarily surgicalinterventions.

One way to prevent vision loss from glaucoma is to lower intraocularpressure with drainage surgery that shunts fluid out of the eye througha channel created during a trabeculectomy procedure, by implanting aflow-controlled drainage device during Minimally Invasive GlaucomaSurgery (MIGS), or by the use of other surgical procedures (e.g., aMinimally Invasive Micro Sclerostomy (MIMS)) or devices. These systemsand procedures allow drainage of the aqueous humor from within the eyeto a small reservoir (termed a “bleb”) under the conjunctiva, from wherethe aqueous humor is later reabsorbed.

However, scar tissue often compromises the bleb or other surroundingstructures (e.g., holes associated with MIMS), ultimately impeding orblocking the flow of excess fluid. Despite compelling therapeuticadvantages over nonsurgical treatments, drainage surgery and devices areclinically limited by postoperative scarring.

Attempts to address this include the application of antimetabolites suchas mitomycin C (MMC) and 5-fluorouracil (5FU). These antimetabolites areused in liquid form and are delivered either by injection or by placingmicrosurgical sponges soaked in the drug directly onto the operativesite underneath the conjunctiva. One of the problems associated withantimetabolites (e.g., MMC and 5FU) is that they do not preserve blebswell. By some reports, the failure rate by three years approaches 50%.

Beta Ophthalmic Applicators

Brachytherapy involves the placement of a radioisotope inside or next tothe area requiring treatment, and has shown safety and efficacy in theclinical management of many diseases. Recently beta brachytherapy hasbeen surprisingly found to be an efficacious therapy in the managementof glaucoma drainage blebs.

Soares (Med Phys 1995, 22(9): 1487-1493) has published a paper detailingthe dosimetry of typical beta ophthalmic applicators that apply adisk-shaped beta RBS to the eye. The Soares work demonstrates that, byinspection of the surface planar isodose figures, the delivered doseacross the radius falls off precipitously in most of these devices. Insome devices, the maximum dose is not the center point. The Soaresresults are similar to earlier publications such as that of Bahrassa andDatta (Int J Radiat Oncol Biol Phys 1983, 9(5): 679-84), which disclosesthat for a typical applicator, the dose at 3.5 mm from the center-pointis only 50% of the center-point maximum dose (see FIG. 1A).

Generally, in legacy beta applicators, it seems that about 90% of thecentral maximum dose falls only within about the inner 2 mm diameter ofthe applicator disk. The dose appears to be reduced significantlyfurther out along the diameter of the applicator disk. This relativeunder-dosing of the periphery is a significant portion of the totalirradiated surface area and a significant portion of the volume of theirradiated target tissue. In addition, Soares also showed irregulardosage patterns and large variation between even the same modelapplicator. Many of the applicators did not seem to have the maximumdose active portion aligned with the center of the applicator.

Safety concerns led to the narrowing of the therapeutic area inophthalmic applicators used for pterygium treatment by attachingfield-shaping masks with the effect of providing a narrowed focalapplication. In 1956, Castroviejo (Trans Am Acad Ophthalmol Otolaryngol.1956, 60(3):486) introduced a series of four screening masks designed tofit snugly over the end of the applicator. The masks are constructed ofstainless steel 0.5 mm thick that substantial blocks the beta radiationand thus restricts irradiation to only that area of the cut out of themasks. These are used to reduce the active surface area of theapplicator. The masks are supplied with circular areas of 3 mm or 5 mmin diameter, and elongated areas 2 mm and 3 mm wide and 8.7 mm long.However, the Castroviejo masks do not provide a uniform dose over thetotal area of the disk applicator. Thus, the previous art of theCastroviejo Masks is not effective for the application of irradiation ofglaucoma drainage blebs.

Brachytherapy Applicator Systems and Devices of the Present Invention

The present invention features systems and devices, e.g., brachytherapysystems and devices, for applying radiation to a treatment area. Forexample, the systems and devices herein may be used to apply betaradiation to a target area in the eye to help maintain functioning blebsand/or drainage holes arising from glaucoma drainage procedures orsurgeries, to help avoid scar formation or wound reversion, to inhibitor reduce fibrogenesis and/or inflammation in the blebs or surroundingareas, etc.

The systems and devices of the present invention feature a handle with amechanism for attaching a radionuclide brachytherapy source therein forproviding beta radiation. The systems and devices also feature radiationattenuation shields that help determine (e.g., optimize) the betaradiation dose distribution across an area of the target, e.g., a targetarea for treatment of glaucoma drainage bleb tissues or other treatmentarea. The radiation attenuation shields may also help attenuate thedistribution of beta radiation to non-target tissue, such as the lens.

The present invention provides the unique technical features of the useof beta radiation instead of, or in combination with, antimetabolites intreatment of conjunctival blebs for prophylaxis and/or treatment ofscar.

The present invention also provides the unique technical feature of thedelivery of a more optimized dose distribution across the surface of thetreatment area (target area) and/or a surface or plane within thetreatment area (target area) as compared to devices previously used (seeFIG. 1A).

Without wishing to limit the present invention to any theory ormechanism, as used herein, the term “optimized dose distribution” mayrefer to a dose across a particular plane on or within the target thatis substantially uniform and therapeutic in dose. For example, the doseacross the particular plane on or within the target varies by no morethan a certain percentage of the maximum dose. As shown in FIG. 1B, theradiation source, e.g., radionuclide brachytherapy source (RBS), is incontact with the eye, and the radiation is emitted to a particulartarget plane within the target/treatment area. The target plane shown inFIG. 1B is a particular distance from the RBS and a particular distancefrom the top of the target area. The size and dimensions of the targetand target plane may vary.

In certain embodiments, the dose across the particular target plane onor within the target varies by no more than 10% of the maximum dose. Incertain embodiments, the dose across the particular plane on or withinthe target varies by no more than 15% of the maximum dose. In certainembodiments, the dose across the particular plane on or within thetarget varies by no more than 20% of the maximum dose. In certainembodiments, the dose across the particular plane on or within thetarget varies by no more than 30% of the maximum dose.

As previously described, doses herein may refer to the dose received bya target surface (e.g., plane surface of a particular size) at aparticular depth. In certain embodiments, the particular plane on orwithin the target is a distance from 0 to 700 microns from the surfaceof the device that contacts the eye tissue. In certain embodiments, theparticular plane on or within the target is a distance from 0 to 100microns from the surface of the device that contacts the eye tissue. Incertain embodiments, the particular plane on or within the target is adistance from 100 to 200 microns from the surface of the device thatcontacts the eye tissue. In certain embodiments, the particular plane onor within the target is a distance from 200 to 400 microns from thesurface of the device that contacts the eye tissue. In certainembodiments, the particular plane on or within the target is a distancefrom 200 to 600 microns from the surface of the device that contacts theeye tissue. In certain embodiments, the particular plane on or withinthe target is a distance from 400 to 600 microns from the surface of thedevice that contacts the eye tissue.

In certain embodiments, the target surface (e.g., plane surface) has adiameter of about 2 mm. In certain embodiments, the target surface(e.g., plane surface) has a diameter of about 3 mm. In certainembodiments, the target surface (e.g., plane surface) has a diameter ofabout 4 mm. In certain embodiments, the target surface (e.g., planesurface) has a diameter of about 5 mm. In certain embodiments, thetarget surface (e.g., plane surface) has a diameter of about 6 mm. Incertain embodiments, the target surface (e.g., plane surface) has adiameter of about 7 mm. In certain embodiments, the target surface(e.g., plane surface) has a diameter of about 8 mm. In certainembodiments, the target surface (e.g., plane surface) has a diameter ofabout 9 mm. In certain embodiments, the target surface (e.g., planesurface) has a diameter of about 10 mm. In certain embodiments, thetarget surface (e.g., plane surface) has a diameter of about 11 mm. Incertain embodiments, the target surface (e.g., plane surface) has adiameter of about 12 mm. In certain embodiments, the target surface(e.g., plane surface) has a diameter from 10 to 14 mm. In certainembodiments, the target surface (e.g., plane surface) has a diameterfrom 6 to 10 mm. In certain embodiments, the target surface (e.g., planesurface) has a diameter from 5 to 12 mm. In certain embodiments, thetarget surface (e.g., plane surface) has a diameter from 6 to 12 mm. Incertain embodiments, the target surface (e.g., plane surface) has adiameter from 8 to 10 mm. In certain embodiments, the target surface(e.g., plane surface) has a diameter from 6 to 8 mm. In certainembodiments, the target surface (e.g., plane surface) has a diameterfrom 7 to 10 mm. In certain embodiments, the target surface (e.g., planesurface) has a diameter from 8 to 11 mm. In certain embodiments, thetarget surface (e.g., plane surface) has a diameter from 9 to 12 mm. Thepresent invention is not limited to the aforementioned dimensions of thetarget surface.

Alternatively, “optimized dose distribution” may also mean that the dosedistribution is varied across the lesion in a specific pattern with theintention to best affect the therapeutic outcome. In one example, thedose distribution across the diameter/plane at the treatment depthvaries such that the areas at the edges of the bleb receive a higherdose relative to the center. In one example, the dose distributionacross the diameter/plane at the treatment depth varies such that thearea at the MIGS device outflow orifice receives a boosted dose comparedto other areas. In one example, the dose distribution across thediameter/plane at the treatment depth varies such that the edges of thebleb and also the area at the MIGS device outflow orifice both receive aboosted dose. In one example, the dose is attenuated over a specifiedarea. In one example, the dose is attenuated over the cornea.

Beta radiation attenuates quickly with depth. In some embodiments, theterm “optimized dose distribution” includes an appropriate dose throughthe depth of the target tissue. The clinical dosage depth may bedetermined by the thickness of the conjunctiva and associated tenon'scapsule of a functional bleb. For MIGS surgery, the focus area may beapproximately 3 mm above the superior limbus. Howlet et al., found themean thickness of the conjunctival and Tenon's layer to be 393±67microns ranging from 194 to 573 microns using optical coherencetomography (OCT) in glaucoma patients (Howlet J et al., Journal ofCurrent Glaucoma Practice 2014, 8(s):63-66). In an earlier study, Zhanget al. found conjunctival thickness to be 238±51 microns in healthyindividuals using OCT analysis and concluded OCT accurately measures thecross-sectional structures of conjunctival tissue with high resolution(Zhang et al., Investigative Ophthalmology & Visual Science 2011,52(10):7787-7791). Based on the Howlet study, the target tissuethickness may range from 150 to 700 microns, or from 10 to 700 microns,etc. In one example, the dose distribution from the surface through thedepth of the target tissue allows for a therapeutic dose within thetissue to the limits of the rapidly attenuating beta rays.

BRIEF SUMMARY OF THE INVENTION

The present invention features ophthalmic applicator systems and devicesfor applying radiation to a treatment area. While the present inventiondescribes applications of the systems and devices for treating glaucomadrainage bleb tissues or drainage holes, the present invention is notlimited to the applications disclosed herein.

The systems and devices comprise a brachytherapy applicator. The systemmay further comprise a radioisotope brachytherapy source (RBS).Generally, the RBS may comprise Strontium-90/Ytrium-90, sealed in adisk-shaped capsule of stainless steel or titanium, although otherappropriate radioisotopes and other appropriate capsule materials can beused. The brachytherapy applicator comprises a handle and a mechanismfor attaching the RBS, and may further comprise other functionalfeatures. The brachytherapy applicator enables application of the RBS tothe eye so as to provide beta brachytherapy.

For example, the present invention features brachytherapy systems forapplying a dose of beta radiation to a target (e.g., portion of aglaucoma drainage bleb, etc.). Briefly, the system comprises a capsystem for accepting a radionuclide brachytherapy source (RBS) forproviding the dose of beta radiation. The cap system is attachable to ahandle, e.g., the cap system may be attachable (directly or indirectly)to the distal portion of the handle. The system may further comprise aradiation attenuation shield that determines (e.g., optimizes) thedistribution of the dose of beta radiation to the target area. Theradiation attenuation shield may be attachable to the cap system, theradiation attenuation shield may be integrated into the cap system, theradiation attenuation shield may be integrated into the handle, etc. Thesystem may further comprise the radionuclide brachytherapy source (RBS).

For example, the present invention features a brachytherapy system forapplying a dose of beta radiation to a target. In certain embodiments,the brachytherapy system comprises a cap system. The cap system maycomprise a base ring having a first end and a second end opposite thefirst end and a cavity therein for accepting a radionuclidebrachytherapy source (RBS) (the first end is open to allow for insertionof the RBS into the cavity); and a barrier surface sealing the secondend of the base ring so as to prevent passing of the RBS through thesecond end. The barrier surface may be constructed from a materialcomprising a synthetic polymer material (e.g., plastic) and the basering is constructed from a material comprising a metal or metal alloy.

In some embodiments, the barrier surface is attached to the second endof the base ring by vacuum forming. In certain embodiments, the basering further comprises a ridge disposed on its outer surface, whereinthe barrier surface extends over the outer surface of the base ring pastthe ridge. In certain embodiments, the exterior surface of the barriersurface is flat. In certain embodiments, the exterior surface of thebarrier surface is concave. In certain embodiments, the exterior surfaceof the barrier surface is convex. In certain embodiments, the systemfurther comprises an RBS disposed in the cavity of the base ring. Incertain embodiments, the system further comprises a radiationattenuation shield attached to the cap system on the second end of thebase ring, the radiation attenuation shield is constructed to regulate adose of beta radiation delivered from an RBS to a target plane of atreatment area.

The present invention also features a brachytherapy system for applyinga dose of beta radiation to a target, wherein the brachytherapy systemcomprises a handle having a distal end; and a cap system disposed on thedistal end of the handle. The cap system comprises a base ring having afirst end and a second end opposite the first end and a cavity thereinfor accepting a radionuclide brachytherapy source (RBS) (the first endis open to allow for insertion of the RBS into the cavity). A barriersurface seals the second end of the base ring so as to prevent passingof the RBS through the second end. In certain embodiments, the barriersurface is constructed from a material comprising a synthetic polymermaterial (e.g., plastic) and the base ring is constructed from amaterial comprising a metal or metal alloy.

With respect to any of the system embodiments herein, in certainembodiments, the barrier surface is attached to the second end of thebase ring by vacuum forming. In some embodiments, the base ring furthercomprises a ridge disposed on its outer surface, wherein the barriersurface extends over the outer surface of the base ring past the ridge.In some embodiments, the system further comprises an RBS disposed in thecavity of the base ring. In some embodiments, the system furthercomprises a radiation attenuation shield attached to the cap system onthe second end of the base ring, the radiation attenuation shield isconstructed to regulate a dose of beta radiation delivered from an RBSto a target plane of a treatment area.

With respect to any of the system embodiments herein, in certainembodiments, the cap system is removably attached to the distal end ofthe handle. In some embodiments, the cap system is indirectly attachedto the distal end of the handle. In certain embodiments, the systemfurther comprises a stem extending from the distal end of the handle,wherein the cap system removably attaches to the stem of the distal end.In some embodiments, the stem is straight. In some embodiments, the stemhas a curvature. In some embodiments, the stem further comprises a discflange disposed on its end opposite the handle, wherein the cap systemremovably attaches to the disc flange of the stem. In some embodiments,the cap system threads onto the disc flange. In some embodiments, thecap system snaps onto the disc flange. In some embodiments, the exteriorsurface of the barrier surface is flat. In some embodiments, theexterior surface of the barrier surface is concave. In some embodiments,the exterior surface of the barrier surface is convex. In certainembodiments, the system further comprises an RBS disposed in the cavityof the base ring. In some embodiments, the RBS comprisesStrontium-90/Ytrium-90. In some embodiments, attaching the cap system tothe distal end of the handle seals an RBS in the cap system. In certainembodiments, the system further comprises a radiation attenuation shieldattachable to the cap system on the second end of the base ring, theradiation attenuation shield is constructed to regulate a dose of betaradiation delivered from an RBS to a target plane of a treatment area.In some embodiments, the system delivers a substantially uniform dose ofbeta radiation to a target plane of a treatment area.

The present invention also features a system comprising a radiationattenuation shield that modifies the output of beta radiation from abeta radionuclide brachytherapy source (RBS) so as to provide asubstantially uniform dose distribution across a treatment radius. Incertain embodiments, the attenuation shield comprises a shield wall witha sealed bottom barrier forming a shield well for accepting the RBS, anda shaping component disposed on an interior surface of the bottombarrier, wherein the shaping component is shaped and constructed toregulate a dose of beta radiation delivered from the RBS to a targetplane of a treatment area. In certain embodiments, the RBS is directlyinserted into the shield well. In certain embodiments, the RBS isindirectly inserted into the shield well.

With respect to any of the system embodiments herein, in certainembodiments, the shaping component is dome shaped. In certainembodiments, the shaping component is a round disk. In certainembodiments, the shaping component is an annulus. In certainembodiments, the shaping component is rectangular. In certainembodiments, the shaping component is a combination of two or morepieces. In certain embodiments, the combination of two or more piecescomprises pieces constructed from different material. In certainembodiments, the combination of two or more pieces comprises piecesconstructed from different sizes. In certain embodiments, the shapingcomponent is constructed from a material comprising stainless steel. Incertain embodiments, the shaping component is constructed from amaterial comprising one or a combination of: stainless steel, titanium,copper, brass, tungsten, tungsten-copper, a metal alloy, or a polymer.In certain embodiments, the radiation attenuation shield is constructedfrom a material comprising a polymer. In certain embodiments, thepolymer is one or a combination of: polycarbonate, PEEK, PEI, PET, PETG,ABS, Epoxy, Polyester, Polystyrene, polyurethane, PVDF, Polyimide, HIPS,or Styrene-butadienne rubber.

With respect to any of the system embodiments herein, in certainembodiments, the shaping component has a thickness from 0.01 mm to 1.5mm. In certain embodiments, the shaping component has a thickness of0.05 mm. In certain embodiments, the shaping component has a thicknessfrom 0.01 mm to 1 mm. In certain embodiments, the shaping component hasa thickness from 0.1 mm to 0.5 mm. In certain embodiments, the shapingcomponent has a diameter from 1 mm to 5 mm. In certain embodiments, theshaping component has a diameter of 3 mm. In certain embodiments, theshaping component has a diameter from 2 mm to 5 mm. In certainembodiments, the shaping component is a stainless steel disc with adiameter of 3 mm and a thickness of 0.05 mm. In certain embodiments, theshaping component is a stainless steel annulus with an outer diameter of3.5 mm, an inner diameter of 2 mm, and a thickness of 0.05 mm. Incertain embodiments, the shaping component attenuates beta radiation by5-90%, e.g., 50%. In certain embodiments, the shaping component isstainless steel foil. In certain embodiments, the shaping component isin a shape of a disc or annulus. In certain embodiments, the shapingcomponent is kidney shaped.

With respect to any of the embodiments herein, in certain embodiments,the target plane of the treatment area has a diameter is from 8 to 12mm. In certain embodiments, the target plane of the treatment area has adiameter is from 9 to 11 mm. In certain embodiments, the dose at anypoint on the target plane of the treatment area is within 10% of a doseat any other point on the target plane of the treatment area. In certainembodiments, the dose at any point on the target plane of the treatmentarea is within 20% of a dose at any other point on the target plane ofthe treatment area. In certain embodiments, the dose at any point on thetarget plane of the treatment area is within 30% of a dose at any otherpoint on the target plane of the treatment area. In certain embodiments,the target plane of the treatment area is 0 to 700 microns from asurface of the system that contacts eye tissue over the treatment areaof the eye. In certain embodiments, the target plane is from 8 to 12 mmin diameter.

With respect to any of the embodiments herein, in certain embodiments,the attenuation shield comprises a shield wall with a sealed bottombarrier forming a shield well for accepting the second end of the basering of the cap system, and a shaping component disposed on an interiorsurface of the bottom barrier, wherein the shaping component is shapedand constructed to regulate a dose of beta radiation delivered from anRBS to a target plane of a treatment area. In certain embodiments, theattenuation shield snaps onto the cap system. In certain embodiments,the attenuation shield is fixedly attached to the cap system. Forexample, in certain embodiments, the attenuation shield is welded to thecap system. In certain embodiments, the attenuation shield is adhered tothe cap system.

In certain embodiments, the system is for single use. In certainembodiments, the cap system is shaped to minimize movement of the RBSonce the RBS is inserted therein. In certain embodiments, the system canbe sterilized.

In certain embodiments, the system is for treating glaucomatreatment-associated blebs. In certain embodiments, the system is forpreventing scar formation associated with implantation of a foreign bodyin an eye. In certain embodiments, the system is for maintaining afunctioning drainage bleb in an eye. In certain embodiments, the systemis for preventing wound reversion in an eye. In certain embodiments, thesystem is for inhibiting fibrogenesis or inflammation associated with ableb.

In some embodiments, the system herein is constructed from a materialcomprising stainless steel, titanium, gold, a ceramic, a polymer, or acombination thereof.

In certain embodiments, the system herein is used in combination withapplication of a drug. In some embodiments, the drug is ananti-metabolite.

The present invention also features brachytherapy systems according tothe present invention for use in a method of treating glaucoma. Themethod may comprise implanting a Minimally Invasive Glaucoma Surgery(MIGS) implant within the eye of a patient being treated for glaucoma,wherein the implant is implanted trans-sclerally to form a bleb in thesubconjunctival space or between the conjunctiva and Tenon's capsule;however, the present invention is not limited to MIGS and may includeMIMS or other appropriate surgical techniques and procedures. The methodcomprises applying beta radiation from a radioisotope in thebrachytherapy system to a target area of the eye, wherein the targetarea is at least a portion of the bleb. In some embodiments, the methodis effective to maintain a functioning drainage bleb.

The present invention also features brachytherapy systems according tothe present invention for use in preventing or reducing scar formationin a draining bleb in a human eye being treated or having been treatedfor glaucoma (e.g., with a minimally invasive glaucoma surgery (MIGS)implant, with MIMS, etc.), characterized in that a radioisotope isadministered to the eye such that beta radiation from the radioisotopeis applied to a target area of the eye, the target area is at least aportion of the bleb.

The present invention also features brachytherapy systems according tothe present invention for use in a method of treating glaucoma in an eyewherein a Minimally Invasive Glaucoma Surgery (MIGS) implant isimplanted trans-sclerally to form a bleb in the subconjunctival space orbetween the conjunctiva and Tenon's capsule, characterized in that thesystem is applied to the eye such that beta radiation from a source ofbeta radiation is applied to a target area of the eye, wherein thetarget area is at least a portion of the bleb.

The present invention also features a method of maintaining afunctioning drainage bleb in the eye of a patient being treated forglaucoma. In some embodiments, the method comprises implanting aMinimally Invasive Glaucoma Surgery (MIGS) implant within the eye,wherein the implant is inserted trans-sclerally and causes formation ofa bleb in the subconjunctival space of the eye or in a space between theconjunctiva and Tenon's capsule, the bleb functions to drain aqueoushumor; however, the present invention is not limited to MIGS and mayinclude MIMS or other appropriate surgical procedures. The methodfurther comprises applying using a brachytherapy system according to thepresent invention a radioisotope that emits beta radiation to a targetarea of the eye, wherein the target area is at least a portion of thebleb; wherein the beta radiation reduces or inhibits a fibrotic processand inflammation that causes bleb failure, and wherein the method iseffective to maintain the drainage function of the bleb.

The present invention also features a method of inhibiting or reducingfibrogenesis and inflammation in a bleb of an eye being treated forglaucoma, wherein a Minimally Invasive Glaucoma Surgery (MIGS) implantis inserted trans-sclerally and causes formation of a bleb in thesubconjunctival space of the eye or in a space between the conjunctivaand Tenon's capsule. In some embodiments, the method comprises applyingusing a brachytherapy system according to the present invention aradioisotope that emits beta radiation to a target area of the eye,wherein the target area is at least a portion of the bleb; wherein thebeta radiation causes cell cycle arrest in fibroblasts on the Tenon'scapsule to inhibit or reduce the fibrotic process and inflammation thatleads to bleb failure.

The present invention also features a method of treating glaucoma. Insome embodiments, the method comprises implanting a Minimally InvasiveGlaucoma Surgery (MIGS) implant within an eye of a patient being treatedfor glaucoma, wherein the implant is inserted between an anteriorchamber of the eye and a subconjunctival space of the eye or between theanterior chamber of the eye and a space between the conjunctiva andTenon's capsule, the implant causes formation of a bleb for drainingaqueous humor; however, the present invention is not limited to MIGS andmay include MIMS or other appropriate surgical procedures. The methodfurther comprises applying using a brachytherapy system according to thepresent invention a radioisotope that emits beta radiation to a targetarea of the eye, wherein the target area is at least a portion of thebleb; wherein the method is effective for reducing an IntraocularPressure (IOP) of the eye.

The present invention also features a method of reducing intraocularpressure (IOP) in an eye. In some embodiments, the method comprisesimplanting a Minimally Invasive Glaucoma Surgery (MIGS) implant withinan eye of a patient being treated for glaucoma, wherein the implant isinserted between an anterior chamber of the eye and a subconjunctivalspace of the eye or between the anterior chamber of the eye and a spacebetween the conjunctiva and Tenon's capsule, the implant causesformation of a bleb for draining aqueous humor; however, the presentinvention is not limited to MIGS and may include MIMS or otherappropriate surgical procedures. The method further comprises applyingusing a brachytherapy system according to the present invention aradioisotope that emits beta radiation to a target area of the eye,wherein the target area is at least a portion of the bleb; wherein thebeta radiation is effective for reducing an Intraocular Pressure (IOP)of the eye.

The present invention also features a method of reducing inflammation inan eye having a foreign body therein, the foreign body being a MinimallyInvasive Glaucoma Surgery (MIGS) implant inserted between an anteriorchamber of the eye and a subconjunctival space of the eye or between theanterior chamber of the eye and a space between the conjunctiva andTenon's capsule, the implant causes formation of a bleb for drainingaqueous humor. In some embodiments, the method comprises applying usinga brachytherapy system according to the present invention a radioisotopethat emits beta radiation to a target area of the eye, wherein thetarget area is at least a portion of the bleb; wherein the method iseffective for reducing inflammation caused by the presence of theforeign body.

The present invention also features a method of modifying a woundhealing process in an eye. In some embodiments, the method comprisesapplying to a target of the eye beta radiation using a brachytherapysystem according to the present invention. In some embodiments, thetarget area is a wound. In some embodiments, the target area is scartissue. In some embodiments, the method is effective to modify cellularsignaling processes that regulate wound healing so as to reduceinflammation and reduce accumulation of scar tissue. In someembodiments, the method is effective for preventing the furtheraccumulation of scar tissue.

The present invention also features a method of breaking up scar tissuein an eye of a patient. In some embodiments, the method comprisesapplying to a target of the eye beta radiation using a brachytherapysystem according to the present invention. In some embodiments, the scartissue is a result of a presence of a foreign body. In some embodiments,the scar tissue is a result of a trabeculectomy. In some embodiments,the scar tissue is a result of an ocular injury. In some embodiments,the method comprises needling scar tissue. In some embodiments, themethod is effective to prevent the further accumulation of scar tissue.In some embodiments, the target is a bleb or a portion thereof, a hole,or a foreign body.

For any of the system embodiments herein, in certain embodiments, theshaping component (198) attenuates from 5-50% of the beta radiation by5-50%. In certain embodiments, the shaping component (198) attenuatesfrom 5-50% of the beta radiation by 25-75%. In certain embodiments, theshaping component (198) attenuates from 5-50% of the beta radiation by10-20%. In certain embodiments, the shaping component (198) attenuatesfrom 5-50% of the beta radiation by 25-50%. In certain embodiments, theshaping component (198) attenuates from 25-75% of the beta radiation by5-50%. In certain embodiments, the shaping component (198) attenuatesfrom 25-75% of the beta radiation by 25-75%. In certain embodiments, theshaping component (198) attenuates from 25-75% of the beta radiation by10-20%. In certain embodiments, the shaping component (198) attenuatesfrom 25-75% of the beta radiation by 25-50%.

Any feature or combination of features described herein are includedwithin the scope of the present invention provided that the featuresincluded in any such combination are not mutually inconsistent as willbe apparent from the context, this specification, and the knowledge ofone of ordinary skill in the art. Additional advantages and aspects ofthe present invention are apparent in the following detailed descriptionand claims.

Terms

Unless otherwise explained, all technical and scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which a disclosed invention belongs. The singularterms “a,” “an,” and “the” include plural referents unless contextclearly indicates otherwise. Similarly, the word “or” is intended toinclude “and” unless the context clearly indicates otherwise. The term“comprising” means that other elements can also be present in additionto the defined elements presented. The use of “comprising” indicatesinclusion rather than limitation. Stated another way, the term“comprising” means “including principally, but not necessary solely”.Furthermore, variation of the word “comprising”, such as “comprise” and“comprises”, have correspondingly the same meanings. In one respect, thetechnology described herein related to the herein describedcompositions, methods, and respective component(s) thereof, as essentialto the invention, yet open to the inclusion of unspecified elements,essential or not (“comprising”).

All embodiments disclosed herein can be combined with other embodimentsunless the context clearly dictates otherwise.

Suitable methods and materials for the practice and/or testing ofembodiments of the disclosure are described below. Such methods andmaterials are illustrative only and are not intended to be limiting.Other methods and materials similar or equivalent to those describedherein can be used. For example, conventional methods well known in theart to which the disclosure pertains are described in various generaland more specific references

Dosimetry techniques include film dosimetry. In one example the RBS isapplied to radiographic film, for example Gafchromic™ film. The dose atvarious depths can also be measured by placing an intervening material,such as Plastic Water™, of known thicknesses between the RBS and thefilm. A transmission densitometer in conjunction with a film opticaldensity vs. dose chart, allows for the film opacity to be measured andthen converted to delivered dose. Other methods includeThermoluminescent methods (TLD chips). TLD chips are small plastic chipswith millimeter dimensions having a crystal lattice that absorbsionizing radiation.

Dose variation is described as that across the diameter assuming acentral point maximum dose. However, in practice it has beendemonstrated that the maximum dose may be off center. Thus, adescription of variation of dose across the diameter may also includethe variation of dose over the area, and though the depth.

In general use in the profession of ophthalmology the term“conjunctivae” may refer to the conjunctivae in combination with theTenon's capsule. Also, in general use in the profession of ophthalmologythe term “conjunctivae” may refer to the conjunctivae alone, notincluding the Tenon's capsule. References herein to “conjunctivae” caninclude either and/or both meanings.

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety for allpurposes. In case of conflict, the present specification, includingexplanations of terms, will control.

Although methods and materials similar or equivalent to those describedherein can be used to practice or test the disclosed technology,suitable methods and materials are described below. The materials,methods, and examples are illustrative only and not intended to belimiting.

In order to facilitate review of the various embodiments of thedisclosure, the following explanations of specific terms are provided:

Beam Modification: Desirable modification in the spatial distribution ofradiation (e.g., within the patient) by insertion of any material in thebeam path. Beam modification increases conformity allowing a higher dosedelivery to the target, while sparing more of normal tissuesimultaneously. There are four main types of beam modification: (1)Shielding: To eliminate radiation dose to some special parts of the zoneat which the beam is directed. In general use is the fabrication oflow-melting-temperature alloy (Lipowitz metal or Cerroblend) shieldingblocks that are custom made for the individual patient and used toshield normal tissue and critical organs. For example, during total bodyirradiation (TBI), customized shielding blocks are positioned in frontof the lungs to reduce radiation dose. (2) Compensation: To allow normaldose distribution data to be applied to the treated zone, when the beamenters obliquely through the body, or where different types of tissuesare present. (3) Wedge filtration: Where a special tilt in isodosecurves is obtained. (4) Flattening: Where the spatial distribution ofthe natural beam is altered by reducing the central exposure raterelative to the peripheral. In general use is a beam flattening filterthat reduces the central exposure rate relative to that near the edge ofthe beam. This technique is used for linear accelerators. The filter isdesigned so that the thickest part is in the center. These are oftenconstructed of copper or brass.

Innovations such as stereotaxic radiotherapy, intensity modulatedradiation therapy, and conformal radiotherapy are also applied towardsthe goal of sparing normal tissue and critical organs. For example,Linear Accelerators designed with Multileaf Collimators have, in manycircumstances, replaced shielding bocks.

Brachytherapy (see also Radionuclide Brachytherapy Source (RBS):According to the American Association of Physicists in Medicine (AAPM),brachytherapy is “the clinical use of small encapsulated radioactivesources at a short distance from the target volume for irradiation ofmalignant tumors or nonmalignant lesions.” Generally, in medicalpractice, brachytherapy can be categorized as topical or plaquebrachytherapy, intracavitary, and interstitial.

Some implementations of brachytherapy employ permanently implantedRadionuclide Brachytherapy Sources (RBSs). For example, in Low Dose Rate(LDR) brachytherapy for prostate cancer, a standard of care treatment,radioactive Iodine-125 RBSs are placed directly into the prostate wherethey remain indefinitely. In another implementation, High Dose Rate(HDR) brachytherapy TheraSpheres are infused into the arteries that feedliver tumors. These microspheres then embolize, lodging themselves inthe liver's capillaries and bathing the malignancy in high levels ofyttrium-90 radiation. In both these implementations, the total dose isgiven by consuming the entire radioisotope. Some other implementationsof brachytherapy employ a transient placement of the RBS. For example,in after-loaded High Dose Rate (HDR) brachytherapy, very tiny plasticcatheters are placed into the prostate gland, and a series of radiationtreatments is given through these catheters. A computer-controlledmachine pushes a single highly radioactive iridium-192 RBS into thecatheters one by one for a specified dwell time at locations throughoutthe volume being irradiated. The catheters are then easily pulled out,and no radioactive material is left at the prostate gland. Anotherexample of transient placement of an RBS includes prophylactic therapyfor restenosis of coronary arteries after stent implantation. This is anon-malignant condition that has been successfully treated by placing acatheter into the coronary artery, then inserting an HDR radioactivesource into the catheter and holding it there for a predetermined timein order to deliver a sufficient dose to the vessel wall.

Drainage Device or Drainage System: Any or a combination of the generaland specific approaches for draining aqueous humor, such as thetherapeutic and devices described herein, e.g., minimally invasiveglaucoma surgery (MIGS) devices and surgery, Minimally Invasive MicroSclerostomy (MIMS) devices and surgery, trabeculectomy surgery,sclerostomy, etc., that are employed to reduce intraocular pressure(IOP) by means of surgical intervention with or without a device.

Flow Controlled Stents (see also Minimally Invasive Glaucoma Surgery(MIGS)): Some MIGS-associated devices control flow of the aqueous humor.For example, the XEN® gel stent (Allergan) is a gelatin andglutaraldehyde tube, which is preloaded in a disposable injector andimplanted using an ab interno approach. The surgeon inserts the injectorthrough a clear cornea incision and tunnels through the sclera at oranterior to Schlemm's canal to deploy the distal portion of the stentwithin the subconjunctival space. This creates a pathway for aqueous toflow from the anterior chamber to the subconjunctival space, forming ableb. Another flow-controlled stent is the InnFocus MicroShunt®(InnFocus, Santen). The surgeon inserts this device into the anteriorchamber through an ab externo approach, creating a bleb in thesubconjunctival space.

Functioning Drainage Bleb: A bleb that is effective for draining aqueoushumor from the eye to reduce intraocular pressure (IOP) of the eye to anappropriate level.

Early bleb grading systems included those proposed by Kronfeld (1969),Migdal and Hitchings (1983), and Picht and Grehn (1998). Subsequent blebgrading systems identified and incorporated a graded assessment ofvarious bleb parameters such as vascularity, height, width, microcysticchanges, encystment and diffuse/demarcated zones.

There are two recently described grading systems for clinical grading offiltering surgery blebs: the Moorfields Bleb Grading System (MBGS) andthe Indiana Bleb Appearance Grading Scale (IBAGS). The MBGS built uponthe system used for this tele-medicine study and expanded it to includean assessment of vascularity away from the center of the bleb and a wayto represent mixed-morphology blebs. In this scheme, central area (1-5),maximal area (1-5), bleb height (1-4) and subconjunctival blood (0-1)were assessed. In addition, three areas of the bleb were gradedseparately for vascularity, including bleb center conjunctiva,peripheral conjunctiva and non-bleb conjunctiva. Vascularity in eacharea was assigned a score from 1 to 5. A study found good inter-observeragreement and clinical reproducibility in the BAGS and MBGS (Wells A P,Ashraff N N, Hall R C, et al. Comparison of two clinical bleb gradingsystems. Ophthalmology 2006; 113:77-83.)

The Moorfields bleb grading system was developed as the importance ofbleb appearance to outcome was realized. Blebs that develop thinavascular zones are at increased risk of leakage and late hypotony aswell as sight threatening bleb related infections.

The Indiana Bleb Appearance Grading Scale is a system for classifyingthe morphologic slit lamp appearance of filtration blebs. The IndianaBleb Appearance Grading Scale contains a set of photographic standardsillustrating a range of filtering bleb morphology selected from theslide library of the Glaucoma Service at the Indiana UniversityDepartment of Ophthalmology. These standards consist of slit lamp imagesfor grading bleb height, extent, vascularity, and leakage with theSeidel test. For grading, the morphologic appearance of the filtrationbleb is assessed relative to the standard images for the 4 parametersand scored accordingly.

For reference, a failed or failing bleb may have “restricted posteriorflow with the so-called ‘ring of steel’,” e.g., a ring of scar tissue orfibrosis adhering the conjunctiva to the sclera at the periphery of thebleb that restricts the flow of aqueous humor (see Dhingra S, Khaw P T.The Moorfields Safer Surgery System. Middle East African Journal ofOphthalmology. 2009; 16(3):112-115). Other attributes of failed orfailing blebs may include cystic appearance and/or changes invascularization and/or scar tissue and/or thinning of the conjunctivaoverlaying the bleb and/or a tense bleb and/or other observable ormeasurable changes as may be included in either the Indiana BlebAppearance Grading Scale or Moorfields Bleb Grading System. Otherfunctional determinates of failed or failing blebs or glaucoma surgerymay include increased IOP, or IOP that has not decreased sufficiently.

Minimally Invasive Glaucoma Surgery (MIGS): MIGS is a recent innovationin the surgical treatment of glaucoma developed to minimize thecomplications from tubes and trabeculectomy. MIGS is a term applied tothe widening range of implants, devices, and techniques that seek tolower intraocular pressure with less surgical risk than the moreestablished procedures. In most cases, conjunctiva-involving devicesrequire a subconjunctival bleb to receive the fluid and allow for itsextraocular resorption. Flow-controlled conjunctiva-involving devicestypically attempt to control flow and lower IOP to normal pressure andalso minimizing hypotony (too low pressure in the eye) by applyingPoiseuille's law of laminar flow to create a tube that is sufficientlylong and narrow to restrict and control outflow. Some MIGS devicesinclude Flow Controlled Stents, microshunts to Shlemm's Canal,Suprachoroidal Devices, and devices for Trabeculotomy. Examples ofmicroshunts to Schlemm's Canal include iStent® (Glaukos®) and Hydrus™(Ivantis). Examples of suprachoroidal devices include CyPass® (Alcon),SoIx® gold shunt (Solx), and iStent Supra® (Glaukos). An example of atrabeculotomy device includes the Trabectome® (NeoMedix) electrocauterydevice.

Planning Treatment Volume or Planning Target Volume (PTV): An area orvolume that encloses all the tissue intended for irradiation. The PTVincludes the clinical target volume or clinical treatment volume (CTV).

Radioactive isotope, radionuclide, radioisotope: An element that has anunstable nucleus and emits radiation during its decay to a stable form.There may be several steps in the decay from a radioactive to a stablenucleus. There are four types of radioactive decay: alpha, betanegative, beta positive, and electron capture. Gamma rays can be emittedby the daughter nucleus in a de-excitation following the decay process.These emissions are considered ionizing radiation because they arepowerful enough to liberate an electron from another atom.

Therapeutic radionuclides can occur naturally or can be artificiallyproduced, for example by nuclear reactors or particle accelerators.Radionuclide generators are used to separate daughter isotopes fromparent isotopes following natural decay.

Non-limiting examples of radioactive isotopes following one of the fourdecay processes are given herein: (1) Alpha decay: radium 226, americium241; (2) Beta minus: iridium 192, cesium 137, phosphorous 32 (P-32),strontium 90 (Sr-90), yttrium 90 (Y-90), ruthenium 106, rhodium-106; (3)Beta positive: fluorine 18; (4) Electron capture: iodine 125, palladium106. Examples of gamma emission include iridium 192 and cesium 137.

Half-life is defined as the time it takes for one-half of the atoms of aradioactive material to disintegrate. Half-lives for variousradioisotopes can range from a few microseconds to billions of years.

The term activity in the radioactive-decay processes refers to thenumber of disintegrations per second. The units of measure for activityin a given source are the curie (Ci) and becquerel (Bq). One (1)Becquerel (Bq) is one disintegration per second.

An older unit is the Curie (Ci), wherein one (1) Ci is 3.7×10¹⁰ Bq.

Radionuclide Brachytherapy Source (RBS) (see also Brachytherapy):According to the US Federal Code of Regulations, a RadionuclideBrachytherapy Source (RBS) is “a device that consists of a radionuclidewhat may be enclosed in a sealed container made of gold, titanium,stainless steel, or platinum and intended for medical purposes to beplaced onto a body surface or into a body cavity or tissue as a sourceof nuclear radiation for therapy.” Other forms of brachytherapy sourcesare also used in practice. For example, a commercially availableconformal source is a flexible, thin film made of a polymer chemicallybound to Phosphorous-32 (P-32). Another product is the TheraSphere, aradiotherapy treatment for hepatocellular carcinoma (HCC) that consistsof millions of microscopic, radioactive glass microspheres (20-30micrometers in diameter) containing Yttrium-90. Other forms ofbrachytherapy employ x-ray generators as sources instead ofradioisotopes.

Sclerostomy: A procedure in which the surgeon makes a small opening inthe sclera to reduce intraocular pressure (IOP), usually in patientswith open-angle glaucoma. It is classified as a type of glaucomafiltering surgery. Minimally invasive micro sclerostomy (MIMS,Sanoculis) is a recent innovative technique that combines the mechanismof conventional trabeculectomy and simple needling. In the course of thesurgery, a sclero-corneal drainage channel is created. The MIMSprocedure can be performed ab externo by creating a sclero-cornealchannel to drain the aqueous humor from the anterior chamber to thesubconjunctival space. The channel created with MIMS is designed toobtain a controlled fluid flow. Laser sclerostomy can be performed in aless invasive manner than standard filtering surgery. Other studies haveexplored the use of laser energy of varying wavelengths, properties, andtissue interaction to create thermal sclerostomies. Several methodsdeliver laser energy by mirrored contact lenses to the internal face ofthe filtration angle or by fiberoptic cables for ab interno or abexterno sclerostomy formation.

Trabeculectomy: A procedure wherein a small hole is made in the scleraand is covered by a thin trap-door. Aqueous humor drains through thetrap door to a bleb. As an example, in some trabeculectomy procedures,an initial pocket is created under the conjunctiva and Tenon's capsuleand the wound bed is treated with mitomycin C soaked sponges using a“fornix-based” conjunctival incision at the corneoscleral junction. Apartial thickness scleral flap with its base at the corneoscleraljunction after cauterization of the flap area is created. Further, awindow opening is created under the flap with a Kelly-punch or a KhawDescemet Membrane Punch to remove a portion of the sclera, Schlemm'scanal, and the trabecular meshwork to enter the anterior chamber. Aniridectomy is done in many cases to prevent future blockage of thesclerostomy. The scleral flap is then sutured loosely back in place withseveral sutures. The conjunctiva is closed in a watertight fashion atthe end of the procedure.

Trans-scleral Drainage Devices: Devices that shunt aqueous humor fromthe anterior chamber to a subconjunctival reservoir. As an example, theEX-PRESS® Glaucoma Filtration Device channels aqueous humor through asecure lumen to a half-thickness scleral flap, creating asubconjunctival filtration bleb. The device's lumen provides astandardized opening for aqueous humor flow while also providing someresistance, which appears to add further stability to the anteriorchamber during surgery and the early post-op period.

Treat, Treatment, Treating: These terms refer to both therapeutictreatments, e.g., elimination of a disease, disorder, or condition, andprophylactic or preventative measures, e.g., preventing or slowing thedevelopment of a disease or condition, reducing at least one adverseeffect or symptom of a disease, condition, or disorder, etc. Treatmentmay be “effective” if one or more symptoms or clinical markers arereduced as that term is defined herein. Alternatively, a treatment maybe “effective” if the progression of a disease is reduced or halted.That is, “treatment” includes not just the improvement of symptoms ordecrease of markers of the disease, but also a cessation or slowing ofprogress or worsening of a symptom that would be expected in absence oftreatment. Beneficial or desired clinical results include, but are notlimited to, alleviation of one or more symptom(s), diminishment ofextent of disease, stabilized (e.g., not worsening) state of disease,delay or slowing of disease progression, amelioration or palliation ofthe disease state, and remission (whether partial or total), whetherdetectable or undetectable. “Treatment” can also mean prolongingsurvival as compared to expected survival if not receiving treatment.Those in need of treatment include those already diagnosed with aparticular disease, disorder, or condition, as well as those likely todevelop a particular disease, disorder, or condition due to geneticsusceptibility or other factors.

Valves: Devices that can be used for glaucoma treatment, wherein insteadof using a natural bleb, these devices use a synthetic reservoir (orplate), which is implanted under the conjunctiva to allow flow ofaqueous fluid. Valve devices include the Baerveldt® implant (PharmaciaCo.), the Ahmed® glaucoma valve (New World Medical), the Krupin-Denvereye valve to disc implant (E. Benson Hood Laboratories), and theMolteno® and Molteno3® drainage devices (Molteno® Ophthalmic Ltd.).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The features and advantages of the present invention will becomeapparent from a consideration of the following detailed descriptionpresented in connection with the accompanying drawings in which:

FIG. 1A shows surface dose profiles for a Sr-90 Source (from Bahrassa,1983) (legacy dose) and a Sr-90 source of the present invention (newdose).

FIG. 1B shows a schematic view of a plane within a treatment area.

FIG. 2 shows a perspective view of an embodiment of a brachytherapyapplicator system of the present invention.

FIG. 3 shows a perspective view of an embodiment of a brachytherapyapplicator system of the present invention.

FIG. 4A shows a detailed view of the brachytherapy applicator system ofFIG. 2.

FIG. 4B shows a detailed view of the base ring of the cap system of FIG.4A.

FIG. 5 shows a detailed view of the system of FIG. 3.

FIG. 6 shows a detailed view of the system of FIG. 3.

FIG. 7 shows a detailed view of the system of FIG. 3.

FIG. 8 shows a perspective view of an embodiment of a brachytherapyapplicator system of the present invention, wherein an RBS is housed ina well.

FIG. 9 shows a perspective view of an embodiment of a brachytherapyapplicator system of the present invention, wherein an RBS is housed ina well.

FIG. 10A shows a cross-sectional view of a cap system of a brachytherapyapplicator of the present invention.

FIG. 10B shows a cross-sectional view of a cap system of a brachytherapyapplicator of the present invention.

FIG. 11A shows a perspective view of a radiation attenuation shield.

FIG. 11B shows side cross-sectional views of non-limiting examples ofradiation attenuation shields. (Cap system not shown.)

FIG. 11C shows a side cross-sectional view of an example of a radiationattenuation shield attached to a cap system with an RBS.

FIG. 12 shows a schematic view of assembly of an example of abrachytherapy applicator.

DETAILED DESCRIPTION OF THE INVENTION

The present invention features ophthalmic applicator systems and devicesfor applying radiation to a treatment area. The systems and devices maycomprise a brachytherapy applicator and may further comprise aradioisotope brachytherapy source (RBS). The systems and devices maycomprise a cap system for accepting an RBS and may further comprise theRBS and/or a handle. The systems and devices of the present inventionprovide for a method of treating blebs or other appropriate structuresor tissues, e.g., structures or tissues associated with glaucomadrainage surgery, e.g., glaucoma procedure conjunctival blebs, with asubstantially uniform dose of beta therapy. While the present inventiondescribes applications of the systems and devices for treating glaucomadrainage bleb tissues or drainage holes, the present invention is notlimited to the applications disclosed herein. For example, the systemsand devices may feature applying beta radiation to ocular wounds, suchas wounds due to the presence of a foreign body or trauma.

Isotopes and Radioactivity

The US Nuclear Regulatory Commission (USNRC) defines radioactivity as“the amount of ionizing radiation released by a material. Whether itemits alpha or beta particles, gamma rays, x-rays, or neutrons, aquantity of radioactive material is expressed in terms of itsradioactivity (or simply its activity), which represents how many atomsin the material decay in a given time period. The units of measure forradioactivity are the curie (Ci) and becquerel (Bq).” Activity in aradioactive-decay process is defined as the number of disintegrationsper second, or the number of unstable atomic nuclei that decay persecond in a given sample. Activity is expressed in the InternationalSystem of Units by the becquerel (abbreviated Bq), which is exactlyequal to one disintegration per second. Another unit that may be used isthe Curie, wherein one curie is approximately the activity of 1 gram ofradium and equals (exactly) 3.7×10¹⁰ becquerel. The specific activity ofradionuclides is relevant when it comes to select them for productionfor therapeutic pharmaceuticals.

By the USNRC definition, absorbed dose is defined as the amount ofradiation absorbed, e.g., the amount of energy that radioactive sourcesdeposit in materials through which they pass or the concentration ofenergy deposited in tissue as a result of an exposure to ionizingradiation. The absorbed dose is equal to the radiation exposure (ions orCi/kg) of the radiation beam multiplied by the ionization energy of themedium to be ionized. Typically, the units for absorbed dose are theradiation absorbed dose (rad) and gray (Gy). Gy is a unit of ionizingradiation dose defined as the absorption of one joule of radiationenergy per kilogram of matter. The rad has generally been replaced bythe Gy in SI derived units. 1 Gy is equivalent to 100 rad.

Radionuclide generators are devices that produce a useful short-livedmedical radionuclide (known as “daughter” products) from the radioactivetransformation of a long-lived radionuclide (called a “parent”). Byhaving a supply of parent on hand at a facility, the daughter iscontinually generated on site. The generator permits ready separation ofthe daughter radionuclide from the parent. One of the most widely usedgenerator devices (often referred as a “cow”) is the technetium 99generator. It allows the extraction of the metastable isotope 99mTc oftechnetium from a source of decaying molybdenum-99. 99Mo has a half-lifeof 66 hours and can be easily transported over long distances tohospitals where its decay product technetium-99m (with a half-life ofonly 6 hours, inconvenient for transport) is extracted and used for avariety of nuclear medicine procedures, where its short half-life isvery useful.

Generators can also be constructed for supply of other daughterradioisotopes. Ruthenium 106 (Ru-106) is a commercially availableradioisotope with a half-life of 668373 days, making it a good candidatefor a parent isotope in a cow or generator. The decay of Ru-106 torhodium-106 (Rh-106) produces only a low energy beta of 39 Key that isnot useful for therapy. However, Rh-106 has an energetic beta decayuseful for brachytherapy: Rh-106 has a half-life of 30 seconds anddecays by beta emission to palladium 106 (Pd-106) with a maximum decayenergy of 3.541 Mev and an average energy of 96.9 Key. As an example, insome embodiments, the present invention features a device loaded from aRuthenium-106 cow with an activity of rhodium-106 providing for the fullprescribed dose. The device can be applied to the target volume todeliver the full activity of its contents. For example, the device maybe placed over the target lesion for 10 half-lives (300 seconds),delivering all its radioactive energy and consuming the rhodium-106,depleting it to palladium.

In some embodiments, the present invention features the use of Ru-106 insecular equilibrium with Rh-106. Ru-106 decays by beta radiation toRh-106. The two isotopes are in secular equilibrium with the decay rateof the combined source controlled by the Ru-106 parent but with thetherapeutic beta radiations emanating from the daughter Rh-106.

Yttrium-90 is commercially available from Strontium-90 cows. As anotherexample, in some embodiments, the present invention features the use ofYttrium-90 with a half-life of 64 hours. Y-90 decays to Zirconium 90(Zr-90), a stable isotope, along three different routes via betaemission, wherein 99.985% of the time it decays with a maximum betaparticle energy of 2.2801 MeV and a mean beta particle energy of 0.9337MeV, or approximately or 1.5×10-13 joules. The other minor decay pathsproduce additional low energy gamma-rays, and electrons. Compared to thedominant path, the radiation doses from these paths are clinicallynegligible.

Currently, strontium-90 is also commercially available. As anotherexample, in some embodiments, the present invention features the use ofStrontium 90 (Sr-90) in secular equilibrium with Yttrium 90 (Y-90).Strontium 90 (Sr-90) decays by beta radiation to Yttrium 90 (Y-90). Theparent Sr-90 isotope has a half-life of 28.79 years. The daughter Y-90isotope has a half-life of 64.0 hours. The two isotopes are in secularequilibrium with the decay rate of the combined source controlled by theSr-90 parent but with the therapeutic beta radiations emanating from thedaughter Y-90 with maximum energy of 2.28 MeV and an average energy of934 keV.

The Planning Target Volume (PTV) or Planning Treatment Volume (PTV) is ageometrical concept introduced for radiation treatment planning. The PTVhas historically been used to ensure that the prescribed dose isactually delivered to all parts of the target tissue. Without limitingthe invention to any particular surgical practice, a medical journalarticle details the surgical creation of the bleb in which “the surgeondissects backward with Westcott scissors to make a pocket approximately10 to 15 mm posteriorly and sufficiently wide to accommodate theantimetabolite sponges.” In this example, the surgeon opened thepotential space under the conjunctiva and Tenon's capsule creating anapproximately 10 to 15 mm diameter bleb site. As an example, in thisembodiment, the PTV could be defined as a disk of diameter 15 mm anddepth of 0.3 mm, containing the conjunctiva and Tenon's capsule tissue.

As an example, a prescription dose of brachytherapy of 10 Gray (1000cGy)is 10 joules/kg absorbed dose throughout the Target Volume. Measurementshave suggested a model Sr-90/Y-90 RBS with Activity of 1.48 GBq producesa surface dose rate of approximately 0.20 Gy per second. To deliver adose of 10 Gy to the Target Volume would require an irradiation time of50 seconds. The number nuclei that decay during this 50 second treatmentwould be 1.48×10⁹ Bq (disintegrations per second)×50 seconds=7.4×10¹⁰.

Biological Effects of Radiation

The biological effectiveness of radiation depends on the linear energytransfer (LET), total dose, fractionation rate, and radiosensitivity ofthe targeted cells or tissues. As radiation interacts with matter, itloses its energy through interactions with atoms in its direct path. Inradiation therapy, LET is defined as the average amount of energy lostper defined distance in tissue, as in the energy deposited into ahandful of cells. LET occurs at different rates in different tissues,and quantification of LET in cellular systems is an important componentof determining correct dosage in radiology. Low LET radiations areX-rays, gamma rays and beta particles.

Radiation induced ionizations can act directly on the cellular moleculesand cause damage, such as DNA damage. Radiation induced ionizations alsocan act indirectly, producing free radicals that are derived from theionization or excitation of the water component of the cell. Exposure ofcells to ionizing radiation induces high-energy radiolysis of H₂O watermolecules into H+ and OH− radicals. These radicals are themselveschemically reactive, and in turn recombine to produce a series of highlyreactive combinations such as superoxide (O₂ ⁻) and peroxide (H₂O₂) thatproduce oxidative damage to molecules, such as DNA, within the cell.Ionizing radiation-induced DNA breaks represent one of the dominantmechanisms of action of beta brachytherapy.

Multiple pathways are involved in the cell after its exposure toionizing radiation. In the cellular response to radiation, severalsensors detect the induced DNA damage and trigger signal transductionpathways. The activation of several signal transduction pathways byionizing radiation results in altered expression of a series of targetgenes.

The promoters or enhancers of these genes may contain binding sites forone or more transcription factors, and a specific transcription factorcan influence the transcription of multiple genes. The transcriptionfactors p53, nuclear factor KB (NF-κB), the specificity protein 1(SP1)-related retinoblastoma control proteins (RCPs), two p53dependentgenes, GADD45 and CDKN1A, and genes associated with the NER pathway(e.g., XPC) are typically upregulated by ionizing radiation exposure.Interestingly, NF-κB activation has been shown to strongly depend oncharged particles' LET, with a maximal activation in the LET range of90-300 keV/μm.

Importantly, the transcribed subset of target genes is critical for thedecision between resuming normal function after cell-cycle arrest andDNA repair, entering senescence, or proceeding through apoptosis incases of severe DNA damage.

Arrest of the cell cycle is an important part of DNA damage response,facilitating DNA repair and maintenance of genomic stability. Regulatorsof cell cycle arrest are activated by phosphorylation by ataxiatelangiectasia mutated (ATM) and ATR. For example, p53 has a shorthalf-life and is stabilized in response to a variety of cellularstresses after phosphorylation by ATM. After exposure to ionizingradiation, phosphorylation of the serine residues 15 and 20 on p53 bycheckpoint kinase 2 (CHK2) reduces its binding to MDM2, which in itsbound state targets p53 for degradation by the proteasome pathway. Thus,dissociation of p53 from MDM2 prolongs the half-life of p53. Otherproteins, such as Pin 1, Parc, and p300, and p300/CBP-associated factor(PCAF) histone acetyltransferases regulate the transactivation activityof p53. For efficient repair, especially in non-dividing cells, cellularlevels of deoxyribonucleotides are increased during the DNA damagerepair by p53-dependent transcriptional induction of the ribonucleotidereductase RRM2B (p53R2). It is accepted that the severity of DNA damageis the critical factor in directing the signaling cascade towardreversible cell cycle arrest or apoptosis. As part of the signalingcascade, the abundance of p53 protein, specific posttranslationalmodifications, and its interaction with downstream effectors, such asGADD45a or p21, may be responsible for directing the cellular responseat this decision point.

Other pathways besides DNA and p53 can be involved in the cellularresponse to exposure to ionizing radiation. For example, ionizingradiation can produce reactive oxygen species (ROS) in the cytoplasm.

Low-dose radiotherapy (LD-RT) is known to exert an anti-inflammatoryeffect. In vitro models have revealed anti-inflammatory effects of LD-RTin doses ranging from 0.1-1.0 Gy on immune cells such as macrophages andneutrophils. Studies have also shown that low-dose radiation therapy hasan anti-inflammatory effect involving diminished CCL20 chemokineexpression and granulocyte/endothelial cell adhesion. An in vitro studyby Khaw et al. (1991, British Journal of Ophthalmology 75:580-583) ofbeta irradiation of fibroblasts in culture found that “radiation reducesthe proliferation of human Tenon's capsule fibroblasts. The doses ofradiation which inhibited cell proliferation more than 50% (at day 7 and14) and yet did not cause a decrease in the cell population were 500,750, and 1000 rads.” The fibroblasts enter a period of growth arrest butdo not die.

The present invention features systems and devices for the applicationof beta radiation used in combination with surgical procedures and/orimplants (e.g., MIGS implants) as described herein. The brachytherapyprovided by the systems and devices herein helps to prevent or reducebleb scarring or failure to maintain a functioning bleb. Without wishingto limit the present invention to any theory or mechanism, it isbelieved that the brachytherapy devices and systems herein may help toinhibit or reduce inflammation and/or fibrogenesis by downregulatingcellular (e.g., fibroblast) activity without cell death.

The application of beta radiation provides a medicament-like treatment,similar to a drug, wherein the beta radiation, when consumed by thecells, causes biological changes in signaling and gene transcription,thereby affecting cellular activity and growth, e.g., cell cycle arrest.

The present invention provides compositions or products that areradioactive compositions (sources of beta radiation). The radioactivecomposition has a therapeutic effect via the generation of betaradiation by, for example, the mechanisms previously discussed. Ingenerating the beta radiation, radioactive composition is consumed(e.g., the product is gradually used up), in that the radioisotope atomsof the beta radioisotope brachytherapy source decay into other nuclides.

Targets of the Eye

As previously discussed, the present invention provides systems anddevices, e.g., ophthalmic applicator systems, brachytherapy systems,etc., for applying beta radiation, e.g., to a treatment area or targetof the eye. In some embodiments, the target is a site of the bleb in aneye being treated for glaucoma with a MIGS implant or MIGS procedure. Insome embodiments, the target is a site of the bleb in an eye treatedwith a trabeculectomy. In some embodiments, the target is a site of thebleb in an eye treated with minimally invasive micro sclerostomy (MIMS).In some embodiments, the target is a site of the hole in an eye treatedwith MIMS. In some embodiments, the target is a site of the implant thatis surgically inserted into the eye for the purpose of treatingglaucoma. In some embodiments, the target is a site of the eyeassociated with pterygium.

In some embodiments, the target area is the entire bleb, e.g., theperimeter of the bleb, the center of the bleb, and the portions of thebleb in between the perimeter and the center. In some embodiments, thetarget area is the perimeter of the bleb, e.g., a ring-shaped targetarea. In some embodiments, the target is the perimeter of the bleb and aportion of the bleb next to the perimeter, e.g., the target may beannulus-shaped. In some embodiments, the target is a portion of the blebin between the center and the perimeter. In some embodiments, the targetis at least a portion of the center of the bleb. The present inventionis not limited to the aforementioned descriptions of target areas. Forexample, in certain embodiments, the target is (or includes) tissuesurrounding the rim of a drainage channel.

In some embodiments, the target is a target other than that associatedwith MIGS/MIMS/trabeculectomy. In some embodiments, the ophthalmictarget is other targets than those associated with glaucoma drainagesurgery. In some embodiments the target is inflammation, autoimmunemediated pathologies, or vascular pathologies of the eye. In someembodiments, the target is associated with infections (for example,Herpes Simplex Keratitis or Tuberculous sclerokeratitis), Cornealulcerations (for example, Moorens), Allergic disorders (for example,Vernal), benign or malignant Tumors (for example, Squamous CellCarcinoma) or benign growths (for example, papillomas), Degenerations(for example, pterygium), Cicitarising disease (for example,pemphigoid), Inflammations (for example, meibomian gland), ocularmanifestations of Stevens-Johnson syndrome, Drug-induced cicatrizingconjunctivitis, Ligneous conjunctivitis, Corneal Vascularization,Pterygia, Vernal Catarrh, Small papillomas of the eyelid, limbalcarcinoma, ocular malignant melamona, nevus pigmentosus of theconjunctiva, hemangioma, chalazion. In some embodiments, the target isin the orbit of the eye. The present invention includes other ophthalmicindications and is not limited to the aforementioned targets.

Brachytherapy Systems and Devices

The brachytherapy systems and devices of the present invention maycomprise (a) a cap system for accepting a radionuclide brachytherapysource (RBS); (b) a cap system and an RBS; (c) a cap system and anapplicator (e.g., a handle); (d) a cap system, an RBS, and an applicator(e.g., a handle); (e) a cap system and a radiation attenuation shield;(f) a cap system, an RBS, and an radiation attenuation shield; (g) a capsystem, a radiation attenuation shield, and an applicator (e.g., ahandle); (h) a cap system, an RBS, radiation attenuation shield, and anapplicator (e.g., a handle); or (i) any other combination of componentsdescribed herein.

(A) Radionuclide Brachytherapy Source (RBS)

The RBS of the present invention is constructed in a manner that isconsistent with the Federal Code of Regulations, but is not limited tothe terms mentioned in the Code. For example, the RBS of the presentinvention may further comprise a substrate. Also, for example, inaddition to being enclosed by the mentioned “gold, titanium, stainlesssteel, or platinum”, in some embodiments the radionuclide (isotope) ofthe present invention may be enclosed by a combination of one or more of“gold, titanium, stainless steel, or platinum”. In some embodiments, theradionuclide (isotope) of the present invention may be enclosed by oneor more layers of an inert material comprising silver, gold, titanium,stainless steel, platinum, tin, zinc, nickel, copper, other metals,ceramics, glass, or a combination of these.

In some embodiments, the radioisotope comprises Strontium-90 (Sr-90),Phosphorus-32 (P-32), Ruthenium 106 (Ru-106), Yttrium 90 (Y-90), or acombination thereof. In some embodiments, the source of beta radiationcomprises Strontium-90 (Sr-90), Phosphorus-32 (P-32), Ruthenium 106(Ru106), Yttrium 90 (Y-90), or a combination thereof. As an example, theRBS may comprise Strontium-90/Ytrium-90, sealed in a disk-shaped capsuleof stainless steel or titanium, although other appropriate radioisotopesand other appropriate capsule materials can be used. In someembodiments, the RBS is fixedly attached to the brachytherapy system. Insome embodiments, the RBS is removably engaged in the brachytherapysystem. In some embodiments, the RBS is engaged or loaded in thebrachytherapy system prior to use.

In some embodiments, the RBS comprises a substrate, a radioactiveisotope (e.g., Sr-90, Y-90, Rh-106, P-32, etc.), and an encapsulation,enclosing the substrate and isotope. In some embodiments, the isotope iscoated on the substrate, and both the substrate and isotope are furthercoated with the encapsulation. In some embodiments, the radioactiveisotope is embedded in the substrate. In some embodiments, theradioactive isotope is part of the substrate matrix. In someembodiments, the encapsulation may be coated onto the isotope, andoptionally, a portion of the substrate. In some embodiments, theencapsulation is coated around the entire substrate and the isotope. Insome embodiments, the radioactive isotope is an independent piece and issandwiched between the encapsulation and the substrate. The presentinvention is not limited to the aforementioned RBS configurations.

In some embodiments, a surface on the substrate is shaped in a manner toprovide a controlled projection of radiation. The substrate may beconstructed from a variety of materials. For example, in someembodiments the substrate is constructed from a material comprising, asilver, an aluminum, a stainless steel, tungsten, nickel, tin,zirconium, zinc, copper, a metallic material, a ceramic material, aceramic matrix, the like, or a combination thereof. In some embodiments,the substrate functions to shield a portion of the radiation emittedfrom the isotope. The encapsulation may be constructed from a variety ofmaterials, for example from one or more layers of an inert materialcomprising a steel, a silver, a gold, a titanium, a platinum, anotherbio-compatible material, the like, or a combination thereof.

Without wishing to limit the present invention to any theory ormechanisms, it is believed that previous brachytherapy sources generallyonly treated the center part of the target or under-dose the peripheralarea and/or overdose the center (see FIG. 1A). The systems of thepresent invention generally provide a more uniform dose across thetarget area, e.g., across a plane within the target area (see FIG. 1A,FIG. 1B). In certain embodiments, the radionuclide brachytherapy source(RBS) may be designed and/or constructed to provide a more substantiallyuniform radiation dose across a plane within the target, e.g., ascompared to previously constructed devices. In certain embodiments, aportion of the brachytherapy system (e.g., cap system, radiationattenuation shield, etc.) may be designed and/or constructed to providea more substantially uniform radiation dose across the target, e.g., ascompared to previously constructed devices. In certain embodiments, aportion of the brachytherapy system (e.g., cap system, radiationattenuation shield, etc.) and the RBS may be designed and/or constructedto provide a more substantially uniform radiation dose across thetarget, e.g., as compared to previously constructed devices. The presentinvention is not limited to the dosimetry described herein, such as thatshown in FIG. 1A. For example, in some embodiments, the system (e.g.,the cap system, the radiation attenuation shield, etc.) is designed suchthat the dose received at the perimeter of the bleb is higher than thatreceived at the center of the bleb.

Iterative computer simulations of output dosimetry may be used todetermine an optimized design of a device (e.g., an optimized design ofthe RBS and/or cap and/or radiation attenuation shield, etc.). Filmdosimetry is a method of measuring radioactive delivery from a sourceand can be used to measure the dose across the target. It can also beused to calibrate or compare radioactive sources or to determine thehomogeneity of the dose pattern.

The RBS may be disc shaped or have an annulus or rounded shape; however,the present invention is not limited to those shapes, and any shape thatachieves a desired dose profile is encompassed herein. The shape of theRBS may help provide a controlled projection of radiation (e.g., atherapeutic dose) onto the target. The shape of the RBS may help theradiation dose to fall off quickly at the periphery of the target(whatever the target is determined to be, e.g., the whole bleb, aportion of the bleb, etc.). This may help keep the radiation within alimited area/volume and may help prevent unwanted exposure of structuressuch as the lens to radiation.

In some embodiments, the RBS has a diameter from 4 to 20 mm. In someembodiments, the RBS has a diameter from 5 to 15 mm. In someembodiments, the RBS has a diameter from 10 to 20 mm. In someembodiments, the RBS has a diameter from 10 to 15 m. In someembodiments, the RBS has a diameter from 5 to 7 mm (e.g., 5 mm, 6 mm, 7mm). In some embodiments, the RBS has a diameter from 7 to 10 mm (e.g.,7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm). In some embodiments,the RBS has a diameter from 9 to 12 mm (e.g., 9 mm, 9.5 mm, 10 mm, 10.5mm, 11 mm, 11.5 mm, 12 mm). In some embodiments, the RBS has a diameterfrom 10 to 14 mm (e.g., 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm,13 mm, 13.5 mm, 14 mm). In some embodiments, the RBS has a diameter from12 to 16 mm (e.g., 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15mm, 15.5 mm, 16 mm). In some embodiments, the RBS has a diameter from 14to 18 mm (e.g., 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm,17.5 mm, 18 mm). In some embodiments, the RBS has a diameter of 3 mm. Insome embodiments, the RBS has a diameter of 4 mm. In some embodiments,the RBS has a diameter of 5 mm. In some embodiments, the RBS has adiameter of 5 mm. In some embodiments, the RBS has a diameter of 6 mm.In some embodiments, the RBS has a diameter of 7 mm. In someembodiments, the RBS has a diameter of 8 mm. In some embodiments, theRBS has a diameter of 9 mm. In some embodiments, the RBS has a diameterof 10 mm. In some embodiments, the RBS has a diameter of 11 mm. In someembodiments, the RBS has a diameter of 12 mm. In some embodiments, theRBS has a diameter of 13 mm. In some embodiments, the RBS has a diameterof 14 mm. In some embodiments, the RBS has a diameter of 15 mm. In someembodiments, the RBS has a diameter of 16 mm. In some embodiments, theRBS has a diameter of 17 mm. In some embodiments, the RBS has a diameterof 18 mm. In some embodiments, the RBS has a diameter of 19 mm. In someembodiments, the RBS has a diameter of 20 mm. In some embodiments, theRBS has a diameter more than 20 mm.

The system delivers a particular radiation dose to the target, e.g., toa plane within the target (e.g., a plane of a certain size representinga portion of the treatment area (e.g., PTV)). In some embodiments, thesystem delivers a radiation dose of 1000 cGy (10Gy) to the target. Insome embodiments, the system delivers a radiation dose of 900 cGy to thetarget. In some embodiments, the system delivers a radiation dose of 800cGy to the target. In some embodiments, the system delivers a radiationdose of 750 cGy to the target. In some embodiments, the system deliversa radiation dose of 600 cGy to the target. In some embodiments, thesystem delivers a radiation dose of 500 cGy to the target. In someembodiments, the system delivers a radiation dose of 400 cGy to thetarget. In some embodiments, the system delivers a radiation dose of 300cGy to the target. In some embodiments, the system delivers a radiationdose of 200 cGy to the target. In some embodiments, the system deliversa radiation dose of 100 cGy to the target. In some embodiments, thesystem delivers a radiation dose of 50 cGy to the target. In someembodiments, the system delivers a radiation dose of 1100 cGy to thetarget. In some embodiments, the system delivers a radiation dose of1200 cGy to the target. In some embodiments, the system delivers aradiation dose of 1300 cGy to the target. In some embodiments, thesystem delivers a radiation dose of 1500 cGy to the target. In someembodiments, the system delivers a radiation dose from 600 cGy and 1500cGy to the target. In some embodiments, the system delivers a radiationdose from 50 cGy to 100 cGy. In some embodiments, the system delivers aradiation dose from 100 cGy to 150 cGy. In some embodiments, the systemdelivers a radiation dose from 150 cGy to 200 cGy. In some embodiments,the system delivers a radiation dose from 200 cGy to 250 cGy. In someembodiments, the system delivers a radiation dose from 250 cGy to 300cGy. In some embodiments, the system delivers a radiation dose from 300cGy to 350 cGy. In some embodiments, the system delivers a radiationdose from 350 cGy to 400 cGy. In some embodiments, the system delivers aradiation dose from 400 cGy to 450 cGy. In some embodiments, the systemdelivers a radiation dose from 450 cGy to 500 cGy. In some embodiments,the system delivers a radiation dose from 500 cGy to 550 cGy. In someembodiments, the system delivers a radiation dose from 550 cGy to 600cGy. In some embodiments, the system delivers a radiation dose from 600cGy to 650 cGy. In some embodiments, the system delivers a radiationdose from 650 cGy to 700 cGy. In some embodiments, the system delivers aradiation dose from 700 cGy to 750 cGy. In some embodiments, the systemdelivers a radiation dose from 750 cGy to 800 cGy. In some embodiments,the system delivers a radiation dose from 800 cGy to 850 cGy. In someembodiments, the system delivers a radiation dose from 850 cGy to 900cGy. In some embodiments, the system delivers a radiation dose from 900cGy to 950 cGy. In some embodiments, the system delivers a radiationdose from 950 cGy to 1000 cGy. In some embodiments, the system deliversa radiation dose from 1000 cGy to 1050 cGy. In some embodiments, thesystem delivers a radiation dose from 1050 cGy to 1100 cGy. In someembodiments, the system delivers a radiation dose from 1100 cGy to 1150cGy. In some embodiments, the system delivers a radiation dose from 1150cGy to 1200 cGy. In some embodiments, the system delivers a radiationdose from 1200 cGy to 1250 cGy. In some embodiments, the system deliversa radiation dose from 1250 cGy to 1300 cGy. In some embodiments, thesystem delivers a radiation dose from 1300 cGy to 1350 cGy. In someembodiments, the system delivers a radiation dose from 1350 cGy to 1400cGy. In some embodiments, the system delivers a radiation dose from 1400cGy to 1450 cGy. In some embodiments, the system delivers a radiationdose from 1450 cGy to 1500 cGy. In some embodiments, the system deliversa radiation dose from 1500 cGy to 1550 cGy. In some embodiments, thesystem delivers a radiation dose from 1550 cGy to 1600 cGy. In someembodiments, the system delivers a radiation dose from 1600 cGy to 1800cGy. In some embodiments, the system delivers a radiation dose from 1800cGy to 2000 cGy. In some embodiments, the system delivers a radiationdose of 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150,1200, 1250, 1300, 1350, 1400, 1450, or 1500 cGy to the target. In someembodiments, the system delivers a radiation dose of 1500 to 3200 cGy.In some embodiments, the system delivers a radiation dose of 3200 to8000 cGy. In some embodiments, the system delivers a radiation dose of8000 cGy to 10000 cGy. In some embodiments, the system delivers aradiation dose of greater than 10000 cGy.

In some embodiments, the system provides a dose of beta radiation to thetarget (e.g., a plane of a particular size/diameter within the treatmentarea), wherein the dose at any point on the target (e.g., a plane of aparticular size/diameter within the treatment area) is within 10% of adose at any other point on the target. In some embodiments, the systemprovides a dose of beta radiation to the target (e.g., a plane of aparticular size/diameter within the treatment area), wherein the dose atany point on the target (e.g., a plane of a particular size/diameterwithin the treatment area) is within 20% of a dose at any other point onthe target. In some embodiments, the system provides a dose of betaradiation to the target (e.g., a plane of a particular size/diameterwithin the treatment area), wherein the dose at any point on the target(e.g., a plane of a particular size/diameter within the treatment area)is within 30% of a dose at any other point on the target.

In some embodiments, the system (e.g., cap system, radiation attenuationshield, etc.) is designed such that the dose received at the perimeterof the bleb is similar to that at the center, e.g., not less than 80% ofthe dose of the center, not less than 90% of the dose at the center,etc. In some embodiments, the system (e.g., cap system, radiationattenuation shield, etc.) is designed such that any point of the targetis within 20% of the dose of any other point of the target, e.g., thevariation of dose across the target is not more than 20%, e.g., at anygiven point the variation is not more than 20%. In some embodiments, thesystem (e.g., cap system, radiation attenuation shield, etc.) isdesigned such that any point of the target is within 15% of the dose ofany other point of the target, e.g., the variation of dose across thetarget is not more than 15%, e.g., at any given point the variation isnot more than 15%. In some embodiments, the system (e.g., cap system,radiation attenuation shield, etc.) is designed such that any point ofthe target is within 10% of the dose of any other point of the target,e.g., the variation of dose across the target is not more than 10%,e.g., at any given point the variation is not more than 10%. In someembodiments, the system (e.g., cap system, radiation attenuation shield,etc.) is designed such that any point of the target is within 8% of thedose of any other point of the target, e.g., the variation of doseacross the target is not more than 8%, e.g., at any given point thevariation is not more than 8%. In some embodiments, the system (e.g.,cap system, radiation attenuation shield, etc.) is designed such thatany point of the target is within 5% of the dose of any other point ofthe target, e.g., the variation of dose across the target is not morethan 5%, e.g., at any given point the variation is not more than 5%. Insome embodiments, the system (e.g., cap system, radiation attenuationshield, etc.) is designed such that any point of the target is within 3%of the dose of any other point of the target, e.g., the variation ofdose across the target is not more than 3%, e.g., at any given point thevariation is not more than 3%.

In some embodiments, the system delivers the prescribed dose in a timefrom 10 seconds to 20 minutes. In some embodiments, the system deliversthe prescribed dose in a time from 20 seconds and 10 minutes. In someembodiments, the system delivers the prescribed dose in a time from 20seconds to 60 seconds. In some embodiments, the system delivers theprescribed dose in a time from 30 seconds to 90 seconds. In someembodiments, the system delivers the prescribed dose in a time from 60seconds to 90 seconds. In some embodiments, the system delivers theprescribed dose in a time from 90 seconds to 2 minutes. In someembodiments, the system delivers the prescribed dose in a time from 2minutes to 3 minutes.

In some embodiments, the system delivers the prescribed dose in a timefrom 3 minutes to 4 minutes. In some embodiments, the system deliversthe prescribed dose in a time from 3 minutes to 5 minutes. In someembodiments, the system delivers the prescribed dose in a time from 3minutes to 6 minutes. In some embodiments, the system delivers theprescribed dose in a time from 4 minutes to 5 minutes. In someembodiments, the system delivers the prescribed dose in a time from 4minutes to 6 minutes. In some embodiments, the system delivers theprescribed dose in a time from 5 minutes to 6 minutes. In someembodiments, the system delivers the prescribed dose in a time from 6minutes to 7 minutes. In some embodiments, the system delivers theprescribed dose in a time from 7 minutes to 8 minutes. In someembodiments, the system delivers the prescribed dose in a time from 8minutes to 9 minutes. In some embodiments, the system delivers theprescribed dose in a time from 9 minutes to 10 minutes. In someembodiments, system delivers the prescribed dose in a time from 10minutes to 12 minutes. In some embodiments, the system delivers theprescribed dose in a time from 12 minutes to 15 minutes. In someembodiments, the system delivers the prescribed dose in a time from 15minutes to 20 minutes.

In some embodiments, the system delivers the prescribed dose within 5seconds. In some embodiments, the system delivers the prescribed dosewithin 10 seconds. In some embodiments, the system delivers theprescribed dose within 15 seconds. In some embodiments, the systemdelivers the prescribed dose within 20 seconds. In some embodiments, thesystem delivers the prescribed dose within 25 seconds. In someembodiments, the system delivers the prescribed dose within 45 seconds.In some embodiments, the system delivers the prescribed dose within 60seconds. In some embodiments, the system delivers the prescribed dosewithin 90 seconds. In some embodiments, the system delivers theprescribed dose within 2 minutes. In some embodiments, the systemdelivers the prescribed dose within 3 minutes. In some embodiments, thesystem delivers the prescribed dose within 4 minutes. In someembodiments, the system delivers the prescribed dose within 5 minutes.In some embodiments, the system delivers the prescribed dose within 6minutes. In some embodiments, the system delivers the prescribed dosewithin 7 minutes. In some embodiments, the system delivers theprescribed dose within 8 minutes. In some embodiments, the systemdelivers the prescribed dose within 9 minutes. In some embodiments, thesystem delivers the prescribed dose within 10 minutes. In someembodiments, the system delivers the prescribed dose within 11 minutes.In some embodiments, the system delivers the prescribed dose within 12minutes. In some embodiments, the system delivers the prescribed dosewithin 13 minutes. In some embodiments, the system delivers theprescribed dose within 14 minutes. In some embodiments, the systemdelivers the prescribed dose within 15 minutes. In some embodiments, thesystem delivers the prescribed dose within 16 minutes. In someembodiments, the system delivers the prescribed dose within 17 minutes.In some embodiments, the system delivers the prescribed dose within 18minutes. In some embodiments, the system delivers the prescribed dosewithin 19 minutes. In some embodiments, the system delivers theprescribed dose within 20 minutes. In some embodiments, the systemdelivers the prescribed dose in a time frame greater than 20 minutes.

In some embodiments, a dose (e.g., a prescribed dose) may be deliveredin a single application. In other embodiments, a dose (e.g., aprescribed dose) may be fractionated and applied in multipleapplications. For example, in some embodiments, radiation (e.g., aprescribed dose) may be applied over the course of 2 applications. Insome embodiments, radiation (e.g., a prescribed dose) may be appliedover the course of 3 applications. In some embodiments, radiation (e.g.,a prescribed dose) may be applied over the course of 4 applications. Insome embodiments, radiation (e.g., a prescribed dose) may be appliedover the course of 5 applications. In some embodiments, radiation (e.g.,a prescribed dose) may be applied over the course of more than 5applications. In some embodiments, radiation (e.g., a prescribed dose)may be applied over the course of 20 applications. In some embodiments,radiation (e.g., a prescribed dose) may be applied over the course ofmore than 20 applications.

Each application may deliver an equal sub-dose. In some embodiments, oneor more of the sub-doses are different. For example, one or more of thesub-doses may be different so as to increase or decrease with eachadditional application.

According to one embodiment, a dose of radiation may be applied prior tothe treatment procedure, e.g., surgery for implantation of a device,e.g., MIGS device, or other appropriate glaucoma procedure, e.g., MIMS.For example, in some embodiments, a dose of radiation may be applied oneor more days prior to a surgery (e.g., insertion of a device, MIMS,etc.). In some embodiments, a dose of radiation may be applied within a24-hour prior before a surgery (e.g., insertion of a device). In someembodiments, a dose of radiation may be applied just prior to a surgery(e.g., insertion of a device, MIMS, etc.), e.g., 1 hour before, 30minutes before, 15 minutes before, 5 minutes before 1 minute before,etc. In some embodiments, a dose of radiation may be applied during aprocedure, e.g., for implantation of a device. In some embodiments, adose of radiation may be applied right after a surgery (e.g.,implantation of a device (e.g., MIGS device), MIMS, etc.), e.g., within1 minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, etc.). In someembodiments, a dose of radiation may be applied before an incision ismade into the conjunctiva. In some embodiments, a dose of radiation maybe applied after an incision is made into the conjunctiva. In otherembodiments, a dose of radiation may be applied after a surgery (e.g.,insertion of a device). In some embodiments, a dose of radiation may beapplied within a 24-hour period after a surgery (e.g., insertion of adevice). In some embodiments, a dose of radiation may be applied withinone to two days after a surgery (e.g., insertion of a device). In someembodiments, a dose of radiation may be applied within 2 or more daysafter a surgery (e.g., insertion of a device). In some embodiments thedose may be applied any time after the glaucoma surgery. In someembodiments, the dose is applied months or years after the glaucomasurgery. For example, a dose may be given to patients that did notreceive a dose during surgery but at a future date have scar or needlingprocedures to break up scar tissue.

(B) Brachytherapy Applicator

The present invention also provides brachytherapy applicators forapplying the beta radiation to the target in the eye. In certainembodiments, the applicator may feature the RBS fixedly attached to theapplicator. For example, the applicator may be manufactured such thatthe RBS is integrated into the applicator prior to distribution orsurgical use. In some embodiments, the applicator is manufactured toaccept the RBS at a later time. For example, the applicator may bemanufactured and distributed, and the RBS may be attached to or insertedinto the applicator prior to its use in surgery.

The applicator may be constructed from any appropriate material, such asa biocompatible material or a combination of materials. Non-limitingexamples of biocompatible materials include, but are not limited to,metals (for example, stainless steel, titanium, gold), ceramics andpolymers.

FIG. 2 and FIG. 3 shows a non-limiting example of brachytherapyapplicators (100) of the present invention. The applicators (100)comprise a handle (110) and a distal portion (120) at the distal end(112) of the handle (110) for engaging and holding the RBS. The distalportion (120) or a portion thereof may be integrated into (e.g., may bepart of) the distal end (112) of the handle (110).

The distal portion shown in FIG. 2 and FIG. 4A features a stem (122)that is attached to, part of, or capable of engaging the distal end(112) of the handle (110). In some embodiments, the stem (122) isgenerally straight, e.g., as shown in FIG. 2. In some embodiments, thestem (122) has a curvature.

Attached to the opposite end of the stem (122) (e.g., the end oppositethe end that engages the handle (110)) is a disc flange (124). The discflange (124) engages a cap system (150), which is used for housing andprotecting the RBS.

For example, as shown in FIG. 4A, the cap system (150) comprises a basering (155) for accepting the RBS (130), e.g., a generally cylindricalwall for encircling the RBS (130). The base ring (155) has an open firstend (151) for accepting the RBS (130) and a sealed second end (152). Thesecond end (152) of the base ring (155) is sealed by a barrier surface(158), e.g., a surface preventing the RBS (130) from falling through thebase ring (155) at the second end (152) (and preventing contact of theRBS with the patient).

The barrier surface (158) may be constructed from a variety ofmaterials. For example, in some embodiments, the barrier surface (158)is constructed from a material comprising a synthetic polymer material(e.g., plastic). The present invention is not limited to a syntheticpolymer material (e.g., plastic) for the construction of the barriersurface (158) of the base ring (155). For example, the barrier surface(158) of the base ring (155) may be constructed from a materialcomprising a metal or metal alloy.

The example shown in FIG. 4A shows a plastic shield (159) that is sealed(e.g., via vacuum, heat, etc.) onto the base ring (155) at the secondend (152) in a way that provides a barrier surface (158) for the basering (155) and wraps around the outer surface of the base ring (155) adistance from the second end (152). In certain embodiments, the outersurface of the base ring (155) comprises a protrusion or ridge (157) andthe plastic shield (159) is attached to the base ring (155) such thatthe top edge (159 a) of the plastic shield (159) extends over the ridge(157). This configuration may help prevent the plastic shield (159) fromunintentionally sliding off of the base ring (155). The presentinvention is not limited to the particular plastic shield (159) orfabrication method described herein.

In some embodiments, the disc flange (124) and cap system (150) engagevia a threading mechanism. For example, a first thread component (161)may be disposed on the disc flange (124) that is capable of engaging asecond thread component (162) disposed on or in the cap system (150),e.g., on or in the base ring (155). The example shown in FIG. 4A shows afirst thread component (161) extending downwardly (e.g., in thedirection opposite the end of the disc flange (124) that engages thestem (122)) and a second thread component within the top end (122) ofthe base ring (155), wherein the first thread component (161) isconfigured to engage the second thread component (162). The presentinvention is not limited to a male threading component on the discflange (124) and a female threading component in the base ring (150),e.g., the disc flange (124) may feature a female threading component andthe cap system (150) may feature a male threading component.

The present invention is not limited to a threading mechanism forengaging the disc flange (124) and cap system (150). For example, insome embodiments, the disc flange (124) and cap system (150) engage viaa snap mechanism or any other appropriate engaging mechanism.

Further, the present invention is not limited to an applicator with astem (122). (or, in certain embodiments, the stem may be considered partof the distal end (112) of the handle (110)). For example, theapplicator system (100) may comprise a handle with a disc flange (124)integrated into or attached to the distal end (112) of the handle (110).

The distal portion (120) shown in FIG. 3 and FIG. 5 features a stem(122) that is attached to, part of, or capable of engaging the distalend (112) of the handle (110). In some embodiments, the stem (122) isgenerally straight. In some embodiments, the stem (122) has a curvature,e.g., as shown in FIG. 5. A disc flange (124), e.g., a component forengaging an RBS, may be attached to the end of the stem (122) (e.g., theend opposite the end that engages the handle (110)).

In some embodiments, the stem (122) is fixedly attached to the handle(110). In some embodiments, the stem (122) is integrated into the handle(110). In some embodiments, the stem (122) is removably attached to thehandle (110). As a non-limiting example, FIG. 6 shows a handle (110)with a shaft or channel (113) disposed in the distal end (112), whereinthe channel (113) is for accepting the stem (122) of the distal portion(120).

Referring to FIG. 7 and the embodiment shown in FIG. 3, the system (100)further comprises a cap system (250), which is used for housing andprotecting the RBS. The cap system (250) can removably engage the discflange (124). For example, the cap system (250) shown in FIG. 7comprises a base ring (255) for accepting an RBS (130). The base ring(255) is a generally cylindrical wall with an open first end foraccepting the RBS (130) and a barrier surface (258), creating a sealedsecond end.

In some embodiments, the cap system (250), e.g., the first end of thebase ring (155) has a snap on ridge to allow the base ring (255) to besnapped onto the disc flange (124). In some embodiments, the base ring(255) features a pull-tab for quick release of the barrier surface (258)of the base ring (255) to allow for release of the RBS (130). In someembodiments, the base ring (255) cannot be reused after its release fromthe applicator (100) (e.g., release from the disc flange (124)). In someembodiments, the base ring (255) helps provide a seal so as to limitfluid access to the RBS and to constrain the RBS.

In some embodiments, the base ring (155, 255) is separate from the RBS(130). In some embodiments, the RBS (130) is integrated into the basering (155, 255).

The applicator (100), e.g., the handle (110) and/or the distal portion(120), is configured to allow for clear visualization of the treatmentand/or the area of the applicator at the interface of the eye (e.g., theapplicator-eye interface, the source-eye interface, etc.). In someembodiments, the applicator (100) is shaped similar to the designs shownin FIG. 2 and FIG. 3, wherein the handle (110) has a generally linearconfiguration. However, the present invention is not limited to theshapes and configurations shown herein. In some embodiments, the handlehas a curvature.

The distal portion is not limited to the configurations shown herein.For example, in some embodiments, the distal portion (120) isarticulated, e.g., the distal portion (120) can be moved and/or angledas desired.

The handle (110) may feature an ergonomic design, such as that shown inFIG. 2 and FIG. 3, or any other appropriate design. The handle (110) maybe designed to allow for extended surgical use, e.g., for comfortablyapplying radiation to a target for a particular length of time, e.g., atime from 0 to 1 minute, from 1 to 2 minutes, from 2 to 3 minutes, from3 to 4 minutes, from 4 to 5 minutes, etc.

The length and width of the handle (110), and the length and width ofthe distal portion (120 (e.g., length of the stem (122), etc.) are notlimited to any particular dimensions. However, the length of the handle(110) may be designed to help limit the surgeon's exposure to radiationbeing emitted from the RBS at the distal end of the applicator (100).

The applicator (100) may further comprise a branding ring (160) or othersimilar component (e.g., see FIG. 6). The branding ring may be a ring ofmaterial, paint, pigment, or other type of marking that distinguishesitself from the handle (110). The branding ring (160) may be used tohelp the user with alignment of the device. In some embodiments, thebranding ring (160) is for design purposes, e.g., for identifying thedesign with the brand.

FIG. 8 and FIG. 9 show alternative embodiments of the system (100) ofthe present invention. In some embodiments, the distal end of the handle(110) comprises a well (180) for accepting the RBS (130). RBS iscontained in a well (150) at the end of the distal portion (120). Thehandle (110) may further comprise a removable cover (182) for sealingand covering the RBS (130) in the well (180). The cover (182) may becapable of moving between at least an open position (wherein the RBS canbe inserted or removed) and a closed position (wherein the RBS is sealedwithin the well and covered by the cover (182)). As shown in FIG. 8, incertain embodiments, the cover (182) may be slidably attached to thehandle (110). In some embodiments, the cover (182) may be removed usinga pull tab (not shown). In certain embodiments, the cover (182) ispivotally attached to the handle (see FIG. 9). The cover (182) may beintegrated into the handle. FIG. 8 and FIG. 9 show the cover (182) inthe open position.

Referring to the well (150) in FIG. 8 and FIG. 9, in some embodiments,the shape of the well (150) helps minimize the movement of the RBS oncethe RBS is in place in the well (150). The well (150) and cover (182)may provide a seal so as to limit fluid access and constrain the RBS toprevent accidental removal of the RBS. In some embodiments, the well(150) is an integral part of the distal portion of the handle (110). Insome embodiments, the well (150) is an integral part of the handle(110).

In some embodiments, the cover (182) works with a locking mechanism toensure secure containment of the RBS. In some embodiments, the cover(182) snaps on to a flange or handle component. In some embodiments, thecover (182) is part of or comprises a means of releasing the RBS fromthe well (150), e.g., after a procedure. In some embodiments, thelocking mechanism cannot be disengaged (e.g., the RBS released) withoutdestruction of the distal portion of the handle (110), the cap system(150, 250), and/or the cover (182), etc. so as to help preventaccidental release of the RBS and/or reuse of the system (100) and/orcap system (150, 250), and/or cover (182), and/or distal portion (120),etc.

The applicator system (100) of the present invention may feature asource release system (RBS release), e.g., a system for releasing theRBS from the handle (110), e.g., the distal portion (120). In someembodiments, the source release (RBS release) provides a destructiverelease of a portion of the system (100), e.g., the cap system (150,250), the cover (182), etc. allowing for the removal of the RBS. In someembodiments, the source release helps ensure the applicator system (100)is for single-use by featuring a destructive mechanism. As anon-limiting example, the release may be a destructive pull tab. In someembodiments, the release may be a destructive twist cap. In someembodiments, the release system is accessible via the handle (110),e.g., a user may be able to activate the release system with a button orlevel on the handle (110). In some embodiments, the release system isaccessible via the distal portion (120).

The cap system, e.g., the barrier surface of the base ring, may be aportion of the interface between the RBS and the surface of the eye. Forexample, the exterior surface of the barrier surface of the base ring ofthe cap system may be the portion of the cap system that contacts theeye. Referring to FIG. 10A and FIG. 10B, in some embodiments, theexterior surface (158 a) of the barrier surface (158) of the base ring(155) is curved. In certain embodiments, the exterior surface (158 a) ofthe barrier surface (158) of the base ring (155) is generally flat. Incertain embodiments, the interior surface (158 b) of the barrier surfaceof the base ring (the surface opposite the exterior surface of thebarrier surface) may be curved (see FIG. 10A). In certain embodiments,the interior surface (155 b) of the barrier surface of the base ring(the surface opposite the exterior surface of the barrier surface) maybe straight (see FIG. 10B). The exterior surface and/or the interiorsurface of the barrier surface of the base ring may be any appropriateshape or configuration.

In some embodiments, the material and/or shape of the cap system (150)and/or other component that is in direct contact with the eye (e.g.,radiation attenuation shield) may modify transmission of the radiationin a shape that is optimized for treatment.

The brachytherapy applicator (100) of the present invention may furthercomprise a radiation attenuation shield (190) (or beam flatteningfilter) for shaping the emission of the radiation in a particularmanner. For example, the radiation attenuation shield (190) of thepresent invention helps to modify (e.g., optimize) the beta radiationdose distribution delivered across (and/or through) the surface fortreatment (e.g., glaucoma bleb tissues). The radiation attenuationshield (190) may modify the output of radiation so as to provide asubstantially uniform dose distribution across the treatment radius. Insome embodiments, the radiation attenuation shield (190) may limit theamount of radiation that reaches non-target tissues such as the lens.

As shown in FIG. 11A, the radiation attenuation shield (190) may beseparate from the RBS and/or cap system (150). For example, theradiation attenuation shield (190) may be removably attachable to thecap system (150), e.g., to the base ring (155, 255). In certainembodiments, the radiation attenuation shield (190) attaches to the capsystem (150) via a snap mechanism. In certain embodiments, the radiationattenuation shield (190) attaches to the cap system (150) via anadhesive mechanism. In certain embodiments, the radiation attenuationshield (190) attaches to the cap system (150) via a magnetic mechanism.The radiation attenuation shield (190) may be attached to the cap system(150) via any appropriate attachment mechanism. For example, in someembodiments, the radiation attenuation shield (190) may be fixedlyattached to the cap system (150), e.g., via welding or other permanentattachment mechanism.

FIG. 11A, FIG. 11B, and FIG. 11C show non-limiting examples of radiationattenuation shields (190). The radiation attenuation shield (190)comprises a shield wall (194) with a sealed bottom barrier (193),forming a shield well (195) for accepting the RBS and/or cap system(150). The shield (190) may be generally cylindrical, however thepresent invention is not limited to a cylindrical shape. The side wall(194) of the shield (190) surrounds at least a portion of the RBS and/orcap system, e.g., as shown in FIG. 11B and FIG. 11C. The shield (190)further comprises a shaping component (198) disposed on the interiorsurface of the bottom barrier (193) for producing a desired amount anddistribution of radiation from the RBS to the exterior surface of theshield (190) (and ultimately the target). In certain embodiments, theshaping component (198) is dome-shaped, e.g., as shown in FIG. 11A, themiddle panel of FIG. 11B, and FIG. 11C. The shaping component (198) maybe any appropriate shape, size, number of pieces, material, combinationof shapes and/or sizes and/or number of pieces and/or materials, etc.,that produces the desired amount and distribution of radiation. Forexample, in certain embodiments, the shaping component (198) is diskshaped. In certain embodiments, the shaping component (198) isrectangular. In some embodiments, the shaping component (198) is acombination of two or more rectangular pieces. In certain embodiments,the shaping component (198) is a foil disc. In certain embodiments, theshaping component (198) is a foil annulus. In certain embodiments, theshaping component (198) is a plastic disc. In certain embodiments, theshaping component (198) is a plastic annulus.

FIG. 11B shows the RBS inserted into the well (195) of the shield (190).FIG. 11C shows the RBS in the cap system (150), e.g., the base ring(155), which is inserted into the well (195) of the shield (190). Thepresent invention is not limited to any of the aforementionedconfigurations.

In some embodiments, the radiation attenuation shield is integrated intothe RBS and/or cap system (150). In some embodiments, the radiationattenuation shield is separate from the RBS and/or cap system.

In some embodiments, the cap system may be combined with an unmaskedRBS. In some embodiments the cap system provides the radiationattenuation shield for an optimized dose distribution. In someembodiments both the construction of the RBS with an integrate maskcombined with the contribution of the radiation attenuation shieldprovides the combined attenuation for an optimized dose distribution.

Other permutations are possible. In some embodiments unmasked cap can becombined with a masked RBS. In some embodiments an unmasked RBS iscombined with an unmasked cap. In some embodiments the radiationattenuation shield is independent of the cap and RBS. In someembodiments a radiation attenuation shield that is separate andindependent from the RBS and cap may be combined with an unmasked RBSand unmasked cap, or with any combination of a masked RBS, unmasked RBS,masked cap or unmasked cap.

The radiation attenuation shield is positioned between the radiationsource (e.g., RBS) and the target tissue beyond the distal end of thedevice. In some embodiments the radiation attenuation shield is placedbetween the RBS and cap. In some embodiments the radiation attenuationshield is placed on the outer surface of the cap.

The radiation attenuation shield may be constructed from one or avariety of materials. In some embodiments, the radiation attenuationshield is constructed from materials of different electron mean freepath across its area.

The radiation attenuation shield of the present invention may bedesigned based on one or a combination of methods, e.g., based on theresults of experiments using, in part, film dosimetry experiments. Inthis method, the density, thickness, diameter, shape and othercharacteristics of the attenuation material is iteratively modified, andthe effect on the distribution of radiation in the target volumemeasured by the optical density of the exposure onto radiographic film.

The radiation attenuation shield of the present invention may bedesigned based on one or a combination of methods, e.g., based on theresults of experiments using, in part, Monte Carlo methods. J. E.Gentle, in International Encyclopedia of Education (Third Edition), 2010“Monte Carlo Methods in Statistics” states that, “Monte Carlo methodsare experiments. Monte Carlo experimentation is the use of simulatedrandom numbers to estimate some functions of a probabilitydistribution.” In a public presentation by K. Nilsen, PhD, Department ofPhysics and Scientific Computing Group University of Oslo, N-0316 Oslo,Norway in Spring 2008 “Monte Carlo simulations can be treated asComputer experiments. The results can be analyzed with the samestatistics tools we would use in analyzing laboratory experiments.” TheLos Alamos Monte Carlo N-Particle Transport Code (MCNP) “can be used forneutron, photon, electron, or coupled neutron/photon/electron transport.Specific areas of application include, but are not limited to, radiationprotection and dosimetry, radiation shielding, radiography, medicalphysics, nuclear criticality safety, Detector Design and analysis,nuclear oil well logging, Accelerator target design, Fission and fusionreactor design, decontamination and decommissioning.” The “codes can beused to judge whether or not nuclear systems are critical and todetermine doses from sources, among other things.”

The radiation attenuation shields allow transmission of the radiation ina shape that is optimized for the surgical wound and/or the diameterabout that of the bleb. The radiation attenuation shields, in general,have intervening material of various transmissive properties that allowfor flatting of the dose across the diameter or over the area. By thesame method, attenuation of the radiation can also be achieved byvarying the surface output of the beta source so that a portion of thesurface has a lower output. By the same method, a uniform dose acrossthe diameter (or a substantially uniform dose across the diameter) canbe obtained by the summation of the contributions of varying the surfaceoutput of the beta source and masking across the diameter (or area).

The present invention features the design of radiation attenuationshields, and/or the output of the beta source, so that the intendedtarget tissue (e.g., PTV) is best and most fully treated while alsolimiting stray dose to the lens and other tissues. The beta radiationsource and/or radiation attenuation shield output may be optimized tothe Planning Treatment Volume(s) specific to the glaucoma drainageprocedure bleb or other target area, while also limiting stray dose tothe lens and other tissues.

The radiation attenuation shields herein may selectively and variablyattenuate the dose across the surface of the radiation attenuationshield. The relative attenuation can be achieved by a number of methodsincluding changes in density, or distance, or variable use of materialsand thickness that alter the radiation electron mean free path.

In some embodiments, the applicator features a cover for temporarilyshielding the RBS and/or for keeping a portion of the applicator and/orRBS sterile. The cover may be attachable to the RBS. In someembodiments, the cover incorporates a radiation window or mask providingfor a substantially uniform dose distribution across the treatmentradius. The cover also provides for a sterile barrier between the RBSand the patient.

Previous legacy brachytherapy devices were designed with the intent thatthe means of application entails the RBS outer casing is applieddirectly in contact to the surgical site on the anterior eye, ofteneither on the conjunctivae or sclera. Thus, it is interpreted that thedevices are applied to the patient without first undergoing formalsterile processing; Rather, the legacy devices are generally cleanedbetween patient cases with a cloth moistened with alcohol only. Forexample, the US Nuclear Regulatory Commission documents (InformationNotice No. 90-58: US NRC, Sep. 11, 1990) the “Typical Manufacturers safehandling instructions: Sterilize the applicator by either: (a) immersingthe applicator in alcohol in a shielded container, or (b) placing acotton swab, sponge, or gauze, dampened with a sterilizing agent, on aflat surface and wiping the treatment end of the applicator across theswab, sponge, or gauze, instead of holding it with the finger.”

While the radiation emitted from the device gives some added comfort ascreating an inhospitable environment for bacteria, this is method ofcleaning is not consistent with modern regulatory requirements forneither sterility nor absence of pyrogenic material. The presentinvention features sterilized systems and devices, as well as methodsfor sterilizing the systems and devices of the present inventionconsistent with modern regulatory requirements.

In some embodiments, the systems of the present invention provide asterile barrier placed between the RBS and the patient. In someembodiments, the sterile barrier also attenuates the radiation so as toprovide a substantially uniform dose across the relevant treatment area.Thus, in some embodiments, the cap system provides the sterile barrier.In some embodiments, the radiation attenuation shield of the presentinvention provides the sterile barrier.

In some embodiments, one or more components of the invention (e.g.,applicator) are constructed from a material that can further shield theuser from the RBS. In some embodiments, a material having a low atomicnumber (Z) may be used for shielding (e.g., polymethyl methacrylate). Insome embodiments, one or more layers of material are used for shielding,wherein an inner layer comprises a material having a low atomic number(e.g., polymethyl methacrylate) and an outer layer comprises lead.

As an example, in some embodiments, the present invention is a deviceloaded from a Ruthenium-106 cow with an activity of rhodium-106providing for the prescribed dose. The device can be applied to thetarget volume to deliver the full activity of its contents. For example,the device may be placed over the target lesion for 10 half-lives (300seconds), delivering all its radioactive energy and consuming therhodium-106, depleting it to palladium.

As an example, in some embodiments, the present invention is anapplicator constructed containing Strontinum-90/Yttrium-90 radioisotopesin secular equilibrium. In some embodiments, the Sr-90/Y-90 is in asealed source brachytherapy device, e.g., constructed of stainlesssteel. The source may be constructed to project a dose of about 1,000cGy per unit time into a sufficient portion of the adjacent PlanningTreatment Volume, e.g., to contain the conjunctival tissue to a depth of0.3 mm. The source may be attached to or integrated into a brachytherapyapplicator, and a radiation attenuation shield may be attached to thesource or integrated with the source. In some embodiments, the source orattenuation shield or other component may be covered with a sterilebarrier. The present invention is not limited to this embodiment, andvariations and combinations of the disclosed features are also coveredin the scope of this application.

FIG. 12 shows a schematic view of the assembly of a brachytherapyapplicator of the present invention. The present invention is notlimited to the applicator and the components thereof shown in FIG. 12.The device shown comprises a handle (110) and a distal portion (120). Inthis example, the distal portion (120) comprises an RBS (130) connectedto a stem (122). The handle (110) comprises a shaft (113) for acceptingthe stem (122) of the distal portion (120). Note the two differentdistal portions shown, wherein one has a straight stem and one has acurved stem. Also shown is an eye interface cap (260), wherein the outersurface of the second end (262) of the eye interface cap (260) is curvedto match the surface of the eye. After the distal portion (120) isattached to the handle (110), the applicator is inserted into the eyeinterface cap (260) via the first end (261) of the eye interface cap(260). The final image is a fully assembled system.

As previously discussed, the shaping component (198) may be constructedin a variety of shapes as appropriate, e.g., the shaping component (198)may be an annulus, a disc, a rectangle (e.g., square), an ellipse,kidney-shaped, etc. In certain embodiments, the shaping component (198)is generally solid. In certain embodiments, the shaping component (198)comprises one or more pores, e.g., a center hole in the example of anannulus. The present invention is not limited to the aforementionedshapes of shaping components.

Without wishing to limit the present invention to any theory ormechanism, the shaping component of the radiation attenuation shield isdesigned to attenuate a portion of the beta radiation being emitted fromthe RBS. For example, in certain embodiments, the shaping componentprovides a 10-20% attenuation of radiation emitted to at least 50% ofthe area of the target plane. In certain embodiments, the shapingcomponent provides a 20-50% attenuation of radiation emitted to at least50% of the area of the target plane. In certain embodiments, the shapingcomponent provides a 30-60% attenuation of radiation emitted to at least50% of the area of the target plane. In certain embodiments, the shapingcomponent provides a 40-70% attenuation of radiation emitted to at least50% of the area of the target plane. In certain embodiments, the shapingcomponent provides a 50-75% attenuation of radiation emitted to at least50% of the area of the target plane.

In certain embodiments, the shaping component provides a 10-20%attenuation of radiation emitted to a portion of the area of the targetplane that is from 5-50% of the total area of the target plane. Incertain embodiments, the shaping component provides a 20-50% attenuationof radiation emitted to a portion of the area of the target plane thatis from 5-50% of the total area of the target plane. In certainembodiments, the shaping component provides a 30-60% attenuation ofradiation emitted to a portion of the area of the target plane that isfrom 5-50% of the total area of the target plane. In certainembodiments, the shaping component provides a 40-70% attenuation ofradiation emitted to a portion of the area of the target plane that isfrom 5-50% of the total area of the target plane. In certainembodiments, the shaping component provides a 50-75% attenuation ofradiation emitted to a portion of the area of the target plane that isfrom 5-50% of the total area of the target plane.

In certain embodiments, the shaping component provides a 10-20%attenuation of radiation emitted to a portion of the area of the targetplane that is from 10-25% of the total area of the target plane. Incertain embodiments, the shaping component provides a 20-50% attenuationof radiation emitted to a portion of the area of the target plane thatis from 10-25% of the total area of the target plane. In certainembodiments, the shaping component provides a 30-60% attenuation ofradiation emitted to a portion of the area of the target plane that isfrom 10-25% of the total area of the target plane. In certainembodiments, the shaping component provides a 40-70% attenuation ofradiation emitted to a portion of the area of the target plane that isfrom 10-25% of the total area of the target plane. In certainembodiments, the shaping component provides a 50-75% attenuation ofradiation emitted to a portion of the area of the target plane that isfrom 10-25% of the total area of the target plane.

The present invention is not limited to the aforementioned ranges ofattenuation and portions of target planes affected by said attenuation.Table 1 below describes non-limiting examples of embodiments wherein theshaping component attenuates the radiation (by a particular percentageor range of percentages) for a particular portion of the total area ofthe target plane.

Portion of Total Area of Amount of Target Plane Affected ExampleAttenuation by the Attenuation 1  5-20%  5-10% 2  5-20% 10-20% 3  5-20%20-30% 4  5-20% 30-40% 5  5-20% 40-50% 6  5-20% 50-60% 7  5-20% 60-70% 8 5-20% 70-80% 9  5-20% 80-90% 10  5-20%  5-25% 11  5-20% 25-50% 12 5-20% 50-75% 13  5-20% 75-90% 14 10-20%  5-10% 15 10-20% 10-20% 1610-20% 20-30% 17 10-20% 30-40% 18 10-20% 40-50% 19 10-20% 50-60% 2010-20% 60-70% 21 10-20% 70-80% 22 10-20% 80-90% 23 10-20%  5-25% 2410-20% 25-50% 25 10-20% 50-75% 26 10-20% 75-90% 27 20-40%  5-10% 2820-40% 10-20% 29 20-40% 20-30% 30 20-40% 30-40% 31 20-40% 40-50% 3220-40% 50-60% 33 20-40% 60-70% 34 20-40% 70-80% 35 20-40% 80-90% 3620-40%  5-25% 37 20-40% 25-50% 38 20-40% 50-75% 39 20-40% 75-90% 4040-60%  5-10% 41 40-60% 10-20% 42 40-60% 20-30% 43 40-60% 30-40% 4440-60% 40-50% 45 40-60% 50-60% 46 40-60% 60-70% 47 40-60% 70-80% 4840-60% 80-90% 49 40-60%  5-25% 50 40-60% 25-50% 51 40-60% 50-75% 5240-60% 75-90% 53 50-75%  5-10% 54 50-75% 10-20% 55 50-75% 20-30% 5650-75% 30-40% 57 50-75% 40-50% 58 50-75% 50-60% 59 50-75% 60-70% 6050-75% 70-80% 61 50-75% 80-90% 62 50-75%  5-25% 63 50-75% 25-50% 6450-75% 50-75% 65 50-75% 75-90% 66 75-90%  5-10% 67 75-90% 10-20% 6875-90% 20-30% 69 75-90% 30-40% 70 75-90% 40-50% 71 75-90% 50-60% 7275-90% 60-70% 73 75-90% 70-80% 74 75-90% 80-90% 75 75-90%  5-25% 7675-90% 25-50% 77 75-90% 50-75% 78 75-90% 75-90%

Kits

The present invention also features kits comprising one or morecomponents of the brachytherapy systems of the present invention. Forexample, in some embodiments, the kit comprises a brachytherapyapplicator, e.g., the applicator without the RBS. For example, the kitmay comprise the applicator with the handle and a cap system forengaging the handle once the RBS is inside the cap system. In someembodiments, the kit comprises a beta radiation source (e.g., RBS) and abrachytherapy applicator. In some embodiments, the kit comprises aportion of the components of the brachytherapy applicator. In someembodiments, the kit further comprises a radiation attenuation shield.

In some embodiments, the kit comprises a brachytherapy applicator (e.g.,the handle portion and the cap system) and an implant for trans-scleralinsertion (e.g., an implant for trans-scleral insertion that forms ableb in the subconjuctival space of the eye (or forms a bleb in thespace between the conjunctive and Tenon's capsule). In some embodiments,the kit comprises a brachytherapy applicator (e.g., the handle portionand the cap system), a radionuclide brachytherapy source, and an implantfor trans-scleral insertion (e.g., an implant for trans-scleralinsertion that forms a bleb in the subconjuctival space of the eye (orforms a bleb in the space between the conjunctive and Tenon's capsule).For example, in certain embodiments, the handle and cap are provided ina kit packaged with a MIGS drainage device.

In some embodiments, the kit is for single use. The kit may be providedin sterile packaging.

Methods

The systems and devices of the present invention may be used for avariety of methods. Non-limiting examples of methods of use of thesystems and devices herein include methods for applying beta radiationto a target of the eye, for example the site of a bleb formed by a MIGSimplant or procedure. Other methods include methods of inhibiting orfibrogenesis or inhibiting or reducing inflammation in a bleb or holeassociated with a MIGS implant or procedure, a trabeculectomy, a MIMSprocedure, etc.

As an example, the systems and devices of the present invention providefor a method of treating glaucoma drainage procedure conjunctival blebswith a substantially uniform dose of beta therapy, e.g., a substantiallyuniform dose of beta therapy across a diameter of about 10 mm.

Other methods include methods to maintain the function of a bleb,methods to enhance the function of a MIGS implant, e.g., by maintaininga functional bleb, methods to enhance the success of MIMS, methods forrepairing a failed trabeculectomy, methods for repairing a failed MIMS,methods to reduce intraocular pressure (IOP), methods to maintain ahealthy IOP, methods for treating glaucoma, etc.

The methods herein comprise applying beta radiation to a target area ofthe eye. In some embodiments, the target area is a site of the bleb oran expected site of the bleb. (Note that the target is not limited to ableb or a portion of a bleb.) In some embodiments, the target areasurrounds the end of an implant. In some embodiments, the target is from2 to 5 mm in diameter. In some embodiments, the target is from 5 to 12mm in diameter. In some embodiments, the target is from 0.3 mm to 0.5 mmin thickness. In some embodiments, the target is from 0.01 mm to 0.7 mmin thickness. In some embodiments, the target is from 0.1 mm to 0.6 mmin thickness. The present invention is not limited to the aforementioneddimensions of the target.

In some embodiments, the method comprises applying the beta radiationprior to a particular surgical procedure, e.g., prior to insertion of aMIGS implant, prior to incision of the conjunctive, prior to creation ofa hole associated with MIMS, etc. In some embodiments, the methodcomprises applying the beta radiation after a particular surgicalprocedure.

In some embodiments, the methods herein comprise introducing a drug to asite, e.g., a site of the MIGS implant, a site of the bleb, a differentpart of the eye.

The present invention also features methods for preparing an applicatorfor emitting beta radiation. In some embodiments, the method comprisesinserting a radionuclide brachytherapy source (RBS) into an applicator,e.g., an appropriate place or cavity in the applicator. In someembodiments, the method comprises attaching the RBS to an applicator.

In some embodiments, the systems and devices of the present inventionmay be used for methods associated with needling procedures, e.g.,procedures to the bleb to free or remove scar tissue and/or cysticstructures in and/or around the bleb and/or surgery site that may laterarise from wound healing or scarring or inflammatory responses to theglaucoma surgery. Needling procedures may affect surgical sitemorphology, restore the function of the surgery and/or lower the IOP.

Without wishing to limit the present invention to any theory ormechanism, it is believed that treating scar tissue formation on a blebformed by a trabeculectomy procedure is different than treating anewly-created (and scar tissue-free) bleb at the time of thetrabeculectomy. In some embodiments, the methods herein compriseapplying beta therapy concomitant with a needling procedure to a blebformed by a trabeculectomy procedure. In some embodiments, the methodsherein comprise applying beta therapy to a trabeculectomy bleb that hasformed scar tissue. In some embodiments, the methods herein compriseapplying beta therapy to a bleb in the eye of a trabeculectomy patientwhere the intraocular pressure (IOP) has increased. In some embodiments,the methods herein comprise applying beta therapy to a bleb where thetrabeculectomy is failing or has failed. In some embodiments, themethods herein comprise applying beta therapy to a bleb in a secondtrabeculectomy, where the first trabeculectomy has failed.

In some embodiments, the methods herein comprise applying beta therapyto a bleb that is failing or has failed. In some embodiments, themethods herein comprise applying beta therapy to a MIGS device bleb thatis failing or has failed. In some embodiments, the methods hereincomprise applying beta therapy to a MIGS device bleb that has formedscar tissue. In some embodiments, the methods herein comprise applyingbeta therapy to a bleb in the eye of a MIGS device patient where theintraocular pressure (IOP) has increased.

In some embodiments, the methods herein comprise applying another drugin addition to beta radiation to the eye. In some embodiments, themethods herein comprise applying another antimetabolite (e.g.,mitomycin-c or 5-fluorouracil) in addition to beta radiation. In someembodiments, the methods comprise administering pharmaceutical eye dropsor a liquid anti-metabolite or other liquid drug. In some embodiments,the drug is administered before, during, and/or after a surgicalprocedure.

The systems and devices (and methods) of the present invention may alsobe applied to wound healing, e.g., wounds in the eye due to foreign bodyinsertion, trauma, ocular surface wounds, etc. One model of woundhealing divides the process into hemostasis, inflammation,proliferation, and remodeling. The first phase of hemostasis beginsimmediately after wounding, with vascular constriction and fibrin clotformation. The clot and surrounding wound tissue releasepro-inflammatory cytokines and growth factors such as transforminggrowth factor (TGF)-β, platelet-derived growth factor (PDGF), fibroblastgrowth factor (FGF), and epidermal growth factor (EGF). Once bleeding iscontrolled, inflammatory cells migrate into the wound and promote theinflammatory phase, which is characterized by the sequentialinfiltration of neutrophils, macrophages, and lymphocytes. In the earlywound, macrophages release cytokines that promote the inflammatoryresponse by recruiting and activating additional leukocytes. Asmacrophages clear these apoptotic cells, they undergo a phenotypictransition to a reparative state that stimulates keratinocytes,fibroblasts, and angiogenesis to promote tissue regeneration.T-lymphocytes migrate into wounds following the inflammatory cells andmacrophages, and peak during the lateproliferative/early-remodelingphase. T-cells regulate many aspects of wound healing, includingmaintaining tissue integrity, defending against pathogens, andregulating inflammation. The proliferative phase generally follows andoverlaps with the inflammatory phase, and is characterized by epithelialproliferation and migration over the provisional matrix within the wound(re-epithelialization). In the reparative dermis, fibroblasts andendothelial cells are the most prominent cell types present and supportcapillary growth, collagen formation, and the formation of granulationtissue at the site of injury. Within the wound bed, fibroblasts producecollagen as well as glycosaminoglycans and proteoglycans, which aremajor components of the extracellular matrix (ECM). Following robustproliferation and ECM synthesis, wound healing enters the finalremodeling phase, which can last for years.

The radiation attenuation masks of the present invention reduce toacceptable medical practice the use of beta irradiation intrabeculectomy as a competitive first-choice therapy. This may beachieved both by: (1) the beta radiation source output is optimized tothe Planning Treatment Volume(s) specific to the trabeculectomy surgicalwound and bleb, and (2) minimizing stray dose to the lens, and thusempowering decreases in the side effects of induced cataract thatotherwise limits selection of this treatment modality.

Of note, by convention dose variation is described as that across thediameter assuming a central point maximum dose. However, in practice ithas been demonstrated that the maximum dose may be off center. Thus, thedescription of dose across the diameter may also include the variationof dose over the area.

Various modifications of the invention, in addition to those describedherein, will be apparent to those skilled in the art from the foregoingdescription. Such modifications are also intended to fall within thescope of the appended claims. Each reference cited in the presentapplication is incorporated herein by reference in its entirety.

Although there has been shown and described the preferred embodiment ofthe present invention, it will be readily apparent to those skilled inthe art that modifications may be made thereto which do not exceed thescope of the appended claims. Therefore, the scope of the invention isonly to be limited by the following claims. Reference numbers recited inthe claims are exemplary and for ease of review by the patent officeonly, and are not limiting in any way. In some embodiments, the figurespresented in this patent application are drawn to scale, including theangles, ratios of dimensions, etc. In some embodiments, the figures arerepresentative only and the claims are not limited by the dimensions ofthe figures. In some embodiments, descriptions of the inventionsdescribed herein using the phrase “comprising” includes embodiments thatcould be described as “consisting of”, and as such the writtendescription requirement for claiming one or more embodiments of thepresent invention using the phrase “consisting of” is met.

The reference numbers recited in the below claims are solely for ease ofexamination of this patent application, and are exemplary, and are notintended in any way to limit the scope of the claims to the particularfeatures having the corresponding reference numbers in the drawings.

What is claimed is:
 1. A brachytherapy system for applying a dose ofbeta radiation to a target, said brachytherapy system comprising: a. ahandle (110) having a distal end (112); and b. a cap system (150)disposed on the distal end (112) of the handle (110), the cap system(150) comprises a base ring (155) having a first end (151) and a secondend (152) opposite the first end (151) and a cavity therein foraccepting a radionuclide brachytherapy source (RBS), the first end (151)is open to allow for insertion of the RBS into the cavity; and a barriersurface (158) sealing the second end (152) of the base ring (155) so asto prevent passing of a RBS through the second end (152), wherein thebarrier surface (158) is constructed from a material comprising asynthetic polymer material and the base ring (155) is constructed from amaterial comprising a metal or metal alloy.
 2. The system of claim 1,wherein the system delivers a substantially uniform dose of betaradiation to a target plane of a treatment area.
 3. The system of claim1, wherein the synthetic polymer material of the barrier surface (158)is plastic.
 4. The system of claim 1, wherein the base ring (155)further comprises a ridge disposed on its outer surface, wherein thebarrier surface (158) extends over the outer surface of the base ring(155) past the ridge (157).
 5. The system of claim 1, wherein the stem(122) further comprises a disc flange (124) disposed on its end oppositethe handle (110), wherein the cap system (150) removably attaches to thedisc flange (124) of the stem (122).
 6. The system of claim 1 furthercomprising an RBS disposed in the cavity of the base ring (155).
 7. Thesystem of claim 6, wherein the RBS comprises Strontium-90/Ytrium-90. 8.The system of claim 1 further comprising a radiation attenuation shield(190) attachable to the cap system on the second end (152) of the basering (155), the radiation attenuation shield (190) is constructed toregulate a dose of beta radiation delivered from an RBS housed in thecavity to a target plane of a treatment area.
 9. The system of claim 8,wherein the radiation attenuation shield is constructed from a materialcomprising a polymer.
 10. The system of claim 8, wherein a dose at anypoint on the target plane of the treatment area is within 20% of a doseat any other point on the target plane of the treatment area.
 11. Thesystem of claim 8, wherein the target plane of the treatment area is 0to 700 microns from a surface of the system that contacts eye tissueover the treatment area of the eye.
 12. The system of claim 8, whereinthe target plane is from 8 to 12 mm in diameter.
 13. The system of claim8, wherein the attenuation shield (190) comprises a shield wall (194)with a sealed bottom barrier (193) forming a shield well (195) foraccepting the second end of the base ring (155) of the cap system (150),and a shaping component (198) disposed on an interior surface of thebottom barrier (193), the shaping component (198) is shaped andconstructed to regulate a dose of beta radiation delivered from an RBSto a target plane of a treatment area.
 14. The system of claim 13,wherein the shaping component (198) is dome shaped, rectangular, a rounddisk, or an annulus.
 15. The system of claim 13, wherein the shapingcomponent (198) is a combination of two or more pieces.
 16. The systemof claim 15, wherein the combination of two or more pieces comprisespieces constructed from different material.
 17. The system of claim 15,wherein the combination of two or more pieces comprises piecesconstructed from different sizes.
 18. The system of claim 13, whereinthe shaping component (198) is constructed from a material comprisingone or a combination of: stainless steel, titanium, copper, brass,tungsten, tungsten-copper, a metal alloy, or a polymer.
 19. The systemof claim 13, wherein the shaping component (198) attenuates from 5-50%of the beta radiation by 5-50%.
 20. The system of claim 13, wherein theshaping component (198) attenuates from 25-75% of the beta radiation by5-50%.
 21. The system of claim 8, wherein the attenuation shield (190)is fixedly attached to the cap system (150).
 22. A brachytherapy systemfor applying a dose of beta radiation to a target, said brachytherapysystem comprising a cap system (150), the cap system (150) comprises abase ring (155) having a first end (151) and a second end (152) oppositethe first end (151) and a cavity therein for accepting a radionuclidebrachytherapy source (RBS), the first end (151) is open to allow forinsertion of the RBS into the cavity; and a barrier surface (158)sealing the second end (152) of the base ring (155) so as to preventpassing of the RBS through the second end (152), wherein the barriersurface (158) is constructed from a material comprising a syntheticpolymer material and the base ring (155) is constructed from a materialcomprising a metal or metal alloy.
 23. The system of claim 22, whereinthe synthetic polymer material is plastic.
 24. The system of claim 22,wherein the base ring (155) further comprises a ridge disposed on itsouter surface, wherein the barrier surface (158) extends over the outersurface of the base ring (155) past the ridge (157).
 25. The system ofclaim 22 further comprising an RBS disposed in the cavity of the basering (155).
 26. The system of claim 22 further comprising a radiationattenuation shield attached to the cap system on the second end (152) ofthe base ring (155), the radiation attenuation shield is constructed toregulate a dose of beta radiation delivered from an RBS to a targetplane of a treatment area.
 27. A system comprising a radiationattenuation shield (190) that modifies the output of beta radiation froma beta radionuclide brachytherapy source (RBS) so as to provide asubstantially uniform dose distribution across a treatment radius,wherein the attenuation shield (190) comprises a shield wall (194) witha sealed bottom barrier (193) forming a shield well (195) for acceptingthe RBS, and a shaping component (198) disposed on an interior surfaceof the bottom barrier (193), the shaping component (198) is shaped andconstructed to regulate a dose of beta radiation delivered from the RBSto a target plane of a treatment area.
 28. The system of claim 27,wherein the shaping component (198) is dome shaped, rectangular, a rounddisk, or an annulus.
 29. The system of claim 27, wherein the shapingcomponent (198) is a combination of two or more pieces.
 30. The systemof claim 29, wherein the combination of two or more pieces comprisespieces constructed from different material.
 31. The system of claim 29,wherein the combination of two or more pieces comprises piecesconstructed from different sizes.
 32. The system of claim 27, whereinthe shaping component (198) is constructed from a material comprisingone or a combination of: stainless steel, titanium, copper, brass,tungsten, tungsten-copper, a metal alloy, or a polymer.
 33. The systemof claim 27, wherein the radiation attenuation shield is constructedfrom a material comprising a polymer.
 34. The system of claim 27,wherein the shaping component (198) attenuates from 5-50% of the betaradiation by 5-50%.
 35. The system of claim 27, wherein the shapingcomponent (198) attenuates from 25-75% of the beta radiation by 5-50%.